A portable MP3 player
MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding, lossy compression format, and algorithm, designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. It was invented by a team of European engineers of Philips, CCETT (Centre commun d'?tudes de t?l?vision et t?l?communications), IRT and Fraunhofer Society, who worked in the framework of the EUREKA 147 DAB digital radio research program, and it became an ISO/IEC standard in 1991.
[edit] Overview
MP3 is an audio-specific compression format. It provides a representation of pulse-code modulation–encoded audio in much less space than straightforward methods, by using psychoacoustic models to discard components less audible to human hearing, and recording the remaining information in an efficient manner. Similar principles are used by JPEG, a lossy image compression format.

[edit] History[edit] Development
MPEG-1 Audio Layer 2 encoding began as the Digital Audio Broadcast (DAB) project managed by Egon Meier-Engelen of the Deutsche Forschungs- und Versuchsanstalt f?r Luft- und Raumfahrt (later on called Deutsches Zentrum f?r Luft- und Raumfahrt, German Aerospace Center) in Germany. This project was financed by the European Union as a part of the EUREKA research program where it was commonly known as EU-147, which ran from 1987 to 1994.
As a doctoral student at Germany's University of Erlangen-Nuremberg, Karlheinz Brandenburg began working on digital music compression in the early 1980s, focusing on how people perceive music. He completed his doctoral work in 1989 and became an assistant professor at Erlangen-Nuremberg. While there, he continued to work on music compression with scientists at the Fraunhofer Society (in 1993 he joined the staff of the Fraunhofer Institute). [1]
In 1991, there were two proposals available: Musicam (known as Layer 2), and ASPEC (Adaptive Spectral Perceptual Entropy Coding). The Musicam technique, as proposed by Philips (The Netherlands), CCETT (France) and Institut f?r Rundfunktechnik (Germany) was chosen due to its simplicity and error robustness, as well as its low computational power associated to the encoding of high quality compressed audio. The Musicam format, based on sub-band encoding, was a key to settle the basis of the MPEG Audio compression format (sampling rates, structure of frames, headers, number of samples per frame). Its technology and ideas were fully incorporated into the definition of ISO MPEG Audio Layer I and Layer II and further on of the Layer III (MP3) format. Under the chairmanship of Professor Mussmann (University of Hannover) the editing of the standard was made under the responsibilities of Leon van de Kerkhof (Layer I) and Gerhard Stoll (Layer II).
A working group consisting of Leon Van de Kerkhof (The Netherlands), Gerhard Stoll (Germany), Leonardo Chiariglione (Italy), Yves-Fran?ois Dehery (France), Karlheinz Brandenburg (Germany) took ideas from Musicam and ASPEC, added some of their own ideas and created MP3, which was designed to achieve the same quality at 128 kbit/s as MP2 at 192 kb/s.
All algorithms were approved in 1991, finalized in 1992 as part of MPEG-1, the first standard suite by MPEG, which resulted in the international standard ISO/IEC 11172-3, published in 1993. Further work on MPEG audio was finalized in 1994 as part of the second suite of MPEG standards, MPEG-2, more formally known as international standard ISO/IEC 13818-3, originally published in 1995.
Compression efficiency of encoders is typically defined by the bit rate because compression rate depends on the bit depth and sampling rate of the input signal. Nevertheless, there are often published compression rates that use the CD parameters as references (44.1 kHz, 2 channels at 16 bits per channel or 2x16 bit). Sometimes the Digital Audio Tape (DAT) SP parameters are used (48 kHz, 2x16 bit). Compression ratios with this reference are higher, which demonstrates the problem of the term compression ratio for lossy encoders.
Karlheinz Brandenburg used a CD recording of Suzanne Vega's song "Tom's Diner" to assess the MP3 compression algorithm. This song was chosen because of its softness and simplicity, making it easier to hear imperfections in the compression format during playbacks. Some jokingly refer to Suzanne Vega as "The mother of MP3". Some more critical audio excerpts (glockenspiel, triangle, accordion, ...) were taken from the EBU V3/SQAM reference compact disc and have been used by professional sound engineers to assess the subjective quality of the MPEG Audio formats.[edit] Going public
A reference simulation software implementation, written in the C language and known as ISO 11172-5, was developed by the members of the ISO MPEG Audio committee in order to produce bit compliant MPEG Audio files (Layer 1, Layer 2, Layer 3). Working in non-real time on a number of operating systems, it was able to demonstrate the first real time hardware decoding (DSP based) of compressed audio. Some other real time implementation of MPEG Audio encoders were available for the purpose of digital broadcasting (radio DAB, television DVB) towards consumer receivers and set top boxes.
Later, on July 7, 1994 the Fraunhofer Society released the first software MP3 encoder called l3enc. The filename extension .mp3 was chosen by the Fraunhofer team on July 14, 1995 (previously, the files had been named .bit). With the first real-time software MP3 player Winplay3 (released September 9, 1995) many people were able to encode and playback MP3 files on their PCs. Because of the relatively small hard drives back in that time (~ 500 MB) the technology was essential to store non-instrument based (see: tracker and MIDI) music for listening on a computer.[edit] MP2
In October 1993, MP2 (MPEG-1 Audio Layer 2) files appeared on the Internet and were often played back using the Xing MPEG Audio Player, and later in a program for Unix by Tobias Bading called MAPlay, which was initially released on February 22, 1994 (MAPlay was also ported to Microsoft Windows).
Initially the only encoder available for MP2 production was the Xing Encoder, accompanied by the program cdda2wav, a CD ripper used for extracting CD audio tracks to Waveform Audio Files.
The Internet Underground Music Archive (IUMA) is generally recognized as the start of the on-line music revolution. IUMA was the Internet's first high-fidelity music web site, hosting thousands of authorized MP2 recordings before MP3 or the web was popularized.[edit] Internet
In the first half of 1995 through the late 1990s, MP3 files began to spread on the Internet. MP3's popularity began to rise rapidly with the advent of Nullsoft's audio player Winamp (released in 1997), the Unix audio player mpg123 and the peer-to-peer file sharing network Napster (released in 1999). These programs made it simple for average users to play back, create, share and collect MP3s.
The small size of MP3 files has enabled widespread peer-to-peer file sharing of music which would previously have been impossible. The major record companies, who argue that such free sharing of music reduces sales, reacted to this by pursuing law-suits against Napster, which was eventually closed down, and eventually against individual users who engaged in file sharing.
Despite the popularity of MP3, online music retailers often use other proprietary formats which are encrypted (known as Digital Rights Management) to prevent users from using purchased music in ways not specifically authorised by the record companies. The record companies argue that this is necessary to prevent the files from being made available on peer-to-peer file sharing networks. However, this has other side effects such as preventing users from playing back their purchased music on different types of devices. Some services, such as eMusic, continue to offer the MP3 format which allows users to playback their music on virtually any device.
As of April 2007, EMI (one of the major record labels) along with Apple Inc., made a joint announcement that EMI would be dropping DRM (Digital Rights Management) from all it's future singles and albums released via the iTunes store, with other on-line distributors set to follow suit (Microsoft making a follow up announcement the week later). The overwhelming popularity of the common mp3 file and it's ubiquitous nature forced the record companies to reassess their position on DRM, and adopt the policy that had been working successfully for years (unrestricted access to the file you have downloaded).[edit] Encoding audio
The MPEG-1 standard does not include a precise specification for an MP3 encoder. The decoding algorithm and file format, as a contrast, are well defined. Implementers of the standard were supposed to devise their own algorithms suitable for removing parts of the information in the raw audio (or rather its MDCT representation in the frequency domain). During encoding 576 time domain samples are taken and are transformed to 576 frequency domain samples. If there is a transient, 192 samples are taken instead of 576. This is done to limit the temporal spread of quantization noise accompanying the transient. (See psychoacoustics.)
As a result, there are many different MP3 encoders available, each producing files of differing quality. Comparisons are widely available, so it is easy for a prospective user of an encoder to research the best choice. It must be kept in mind that an encoder that is proficient at encoding at higher bit rates (such as LAME, which is in widespread use for encoding at higher bit rates) is not necessarily as good at other, lower bit rates.[edt] Decoding audio
Decoding, on the other hand, is carefully defined in the standard. Most decoders are "bitstream compliant", meaning that the decompressed output they produce from a given MP3 file will be the same (within a specified degree of rounding tolerance) as the output specified mathematically in the ISO/IEC standard document. The MP3 file has a standard format which is a frame consisting of 384, 576, or 1152 samples (depends on MPEG version and layer) and all the frames have associated header information (32 bits) and side information (9, 17, or 32 bytes, depending on MPEG version and stereo/mono). The header and side information help the decoder to decode the associated Huffman encoded data correctly.
Therefore, comparison of decoders is usually based on how computationally efficient they are (i.e., how much memory or CPU time they use in the decoding process).[edit] Audio quality
When creating an MP3 file, there is a trade-off between the amount of space used and the sound quality of the result. Typically, the user is allowed to set a bit rate which specifies how many kilobits the file may use per second of audio. The lower the bit rate used, the lower will be the audio quality. Likewise, the higher the bitrate used, the higher quality the resulting MP3 will be.
MP3 files encoded with a lower bit rate will generally play back at a lower quality. With too low a bit rate, "compression artifacts" (i.e., sounds that were not present in the original recording) may be audible in the reproduction. A good demonstration of compression artifacts is provided by the sound of applause: it is hard to compress because of its randomness and sharp attacks. Therefore compression artifacts can be heard as ringing or pre-echo.
As well as the bit rate of the encoded file, the quality of MP3 files depends on the quality of the encoder and the difficulty of the signal being encoded. As the MP3 standard allows quite a bit of freedom with encoding algorithms, different encoders may feature quite different quality, even when targeting similar bit rates. As an example, in a public listening test featuring two different MP3 encoders at about 128kbps[2], one scored 3.66 on a 1–5 scale, while the other scored only 2.22.
Quality is heavily dependent on the choice of encoder and encoding parameters. While quality around 128kbps was somewhere between annoying and acceptable with older encoders, modern MP3 encoders can provide very good quality at those bitrates [3] (01/2006), not statistically different from quality provided by AAC, the technical successor of MP3. However, in 1998, MP3 at 128kbps was only providing quality equivalent to AAC-LC at 96kbps and MP2 at 192kbps[4].
The transparency threshold of MP3 can be estimated to be at about 128k with good encoders on typical music as evidenced by its strong performance in the above test, however some particularly difficult material can require 192k or higher. As with all lossy formats, some samples can not be encoded to be transparent for all users.
The simplest type of MP3 file uses one bit rate for the entire file - this is known as Constant Bit Rate (CBR) encoding. Using a constant bit rate makes encoding simpler and faster. However, it is also possible to create files where the bit rate changes throughout the file. These are known as Variable bit rate (VBR) files. The idea behind this is that, in any piece of audio, some parts will be much easier to compress, such as silence or music containing only a few instruments, while others will be more difficult to compress. So, the overall quality of the file may be increased by using a lower bit rate for the less complex passages and a higher one for the more complex parts. With some encoders, it is possible to specify a given quality, and the encoder will vary the bitrate accordingly. Users who know a particular "quality setting" which is transparent to their ears can use this value when encoding all of their music, and not need to worry about performing personal listening tests on each piece of music to determine the correct settings.
In listening tests, MP3 encoders have performed significantly worse than those using more modern compression methods (such as AAC) at low bit rates. In a 2004 public listening test at 32 kbit/s[5], the LAME MP3 encoder scored only 1.79/5 - behind all modern encoders - with Nero Digital HE AAC scoring 3.30/5.
It is also important to note that perceived quality can be influenced by listening environment (ambient noise), listener attention, and listener training.[edit] Bit rate
Several bit rates are specified in the MPEG-1 Layer 3 standard: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s, and the available sampling frequencies are 32, 44.1 and 48 kHz. A sample rate of 44.1 kHz is almost always used since this is also used for CD audio, the main source used for creating MP3 files. A greater variety of bitrates are used on the internet. 128 kbit/s is the most common since it typically offers very good audio quality in a relatively small space. 192 kbit/s is often used by those who notice artifacts at lower bitrates. By contrast, uncompressed audio as stored on a compact disc has a bit rate of 1411.2 kb/s (16 bits/sample ? 44100 samples/second ? 2 channels).
Some additional bit rates and sample rates were made available in the MPEG-2 and the (unofficial) MPEG-2.5 standards: bit rates of 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 kb/s and sample rates of 8, 11.025, 12, 16, 22.05 and 24 kHz.
Non-standard bit rates up to 640 kb/s can be achieved with the LAME encoder and the --freeformat option, but few MP3 players can play those files. Gabriel Bouvigne, a principal developer of the LAME project, says that the freeformat option is compliant with the standard but, according to the standard, decoders are only required to be able to decode streams up to 320 kbit/s.[6][edit] File structure
FPRIVATE "TYPE=PICT;ALT=" MP3 File Structure
An MP3 file is made up of multiple MP3 frames which consist of the MP3 header and the MP3 data. This sequence of frames is called an Elementary stream. Frames are independent items: one can cut the frames from a file and an MP3 player would be able to play it. The MP3 data is the actual audio payload. The diagram shows that the MP3 header consists of a sync word which is used to identify the beginning of a valid frame. This is followed by a bit indicating that this is the MPEG standard and two bits that indicate that layer 3 is being used, hence MPEG-1 Audio Layer 3 or MP3. After this, the values will differ depending on the MP3 file. ISO/IEC 11172-3 defines the range of values for each section of the header along with the specification of the header. Most MP3 files today contain ID3 metadata which precedes or follows the MP3 frames; this is also shown in the diagram.[edit] Design limitations
There are several limitations inherent to the MP3 format that can not be overcome by any MP3 encoder.
Newer audio compression formats such as Vorbis and AAC no longer have these limitations.
In technical terms, MP3 is limited in the following ways:
Bit rate is limited to a maximum of 320 kb/s (while some encoders can create higher bit rates, there is little-to-no support for these higher bit rate mp3s)
Time resolution can be too low for highly transient signals, causing some smearing of percussive sounds
Frequency resolution is limited by the small long block window size, decreasing coding efficiency
No scale factor band for frequencies above 15.5/15.8 kHz
Joint stereo is done on a frame-to-frame basis
Encoder/decoder overall delay is not defined, which means lack of official provision for gapless playback. However, some encoders such as LAME can attach additional metadata that will allow players that are aware of it to deliver seamless playback.
Nevertheless, a well-tuned MP3 encoder can perform competitively even with these restrictions.[edit] ID3 and other tags
Main articles: ID3 and APEv2 tag
A "tag" in a compressed audio file, is a section of the file that contains metadata such as the title, artist, album, track number or other information about the file's contents.
As of 2006, the most widespread standard tag formats are ID3v1 and ID3v2, and the more recently introduced APEv2.
APEv2 was originally developed for the MPC file format (see the APEv2 specification). APEv2 can coexist with ID3 tags in the same file, but it can also be used by itself.
Tag editing functionality is often built-in to MP3 players and editors, but there also exist tag editors dedicated to the purpose.[edit] Volume normalization
As compact discs and other various sources are recorded and mastered at different volumes, it is useful to store volume information about a file in the tag so that at playback time, the volume can be dynamically adjusted.
A few standards for encoding the gain of an MP3 file have been proposed. The idea is to normalize the average volume (not the volume peaks) of audio files, so that the volume does not change between consecutive tracks. This should not be confused with dynamic range compression (DRC) which is a form of normalization used in audio mastering.
The most popular and widely used solution for storing replay gain is known simply as "Replay Gain". Typically, the average volume and clipping information about audio track is stored in the metadata tag.
One can download audio converting software to change the formats.[edit] Licensing and patent issues
A large number of different organizations have claimed ownership of patents necessary to implement MP3 (decoding and/or encoding). These different claims have led to a number of legal actions, and legal threats, from a variety of sources, resulting in uncertainty about what is necessary to legally create MP3-supporting products with MP3 support in countries that permit software patents.
The various patents claimed to cover MP3 by different patent-holders have many different expiration dates, ranging from 2007 to 2017 in the U.S. [7]. However, U.S. patents can only last up to 20 years, and MP3 was released as a specification in 1991, so if U.S. courts applied U.S. law, no patent could apply beyond 2011 to MP3 itself.[8] In the U.S., any patent claiming to cover the fundamentals of MP3 after 2012 should (by law) be struck down as an invalid patent, due to the existence of published prior art (the MP3 specification) more than a year before the patent's filing. If it had been published earlier (such as in public drafts), the latest date would be even earlier. However, it is unclear if U.S. courts would enforce this. The situation in other countries that permit software patents is similar.
Thomson Consumer Electronics claims to control MP3 licensing of the MPEG-1/2 Layer 3 patents in many countries, including the United States, Japan, Canada and EU countries[1]. Thomson has been actively enforcing these patents. Due to different practices in different European countries when granting patents for computer-implemented inventions under the European Patent Convention, it is unclear whether national European courts would uphold the patents.
For current information about Fraunhofer IIS and Thomson's patent portfolio and licensing terms and fees see their website mp3licensing.com. MP3 license revenues generated ca. 100 million Euro revenue to the Fraunhofer Society in 2005. [2]
In September 1998, the Fraunhofer Institute sent a letter to several developers of MP3 software stating that a license was required to "distribute and/or sell decoders and/or encoders". The letter claimed that unlicensed products "infringe the patent rights of Fraunhofer and THOMSON. To make, sell and/or distribute products using the [MPEG Layer-3] standard and thus our patents, you need to obtain a license under these patents from us." [3]
These patent issues significantly slowed the development of unlicensed MP3 software[citation needed] and led to increased focus on creating and popularizing alternatives such as WMA and Ogg Vorbis. Microsoft, the makers of the Windows operating system, chose to move away from MP3 to their own proprietary Windows Media formats to avoid the licensing issues associated with the patents[citation needed]. Until the key patents expire, unlicensed encoders and players appear to be infringing articles in countries that recognize those patents.
In spite of the patent restrictions, the perpetuation of the MP3 format continues; the reasons for this appear to be the network effects caused by:
familiarity with the format,
the large quantity of music now available in the MP3 format,
the wide variety of existing software and hardware that takes advantage of the file format,
the lack of DRM restrictions, which makes MP3 files easy to edit, copy and distribute over networks,
the majority of home users not knowing or not caring about the patents controversy, who often do not consider such legal issues in choosing their music format for personal use.
Additionally, patent holders declined to enforce license fees on open source decoders, allowing many free MP3 decoders to develop.[citation needed] Furthermore, while attempts have been made to discourage distribution of encoder binaries, Thomson has stated that individuals using free MP3 encoders are not required to pay fees. Thus while patent fees have been an issue for companies attempting to use MP3, they have not meaningfully impacted users, allowing the format to grow in popularity.
Sisvel S.p.A. [4] and its US subsidiary Audio MPEG, Inc. [5] previously sued Thomson for patent infringement on MP3 technology[6], but those disputes were resolved in November 2005 with Sisvel granting Thomson a license to their patents. Motorola also recently signed with Audio MPEG to license MP3-related patents.
In September 2006 German officials seized MP3 players from SanDisk's booth at the IFA show in Berlin after an Italian patents firm won an injunction on behalf of Sisvel against SanDisk in a dispute over licencing rights. The injunction was later reversed by a Berlin judge [7]; but that reversal was in turn blocked the same day by another judge from the same court, "bringing the Patent Wild West to Germany" in the words of one commentator. [8].
On February 16, 2007, Texas MP3 Technologies sued Apple, Samsung Electronics, and Sandisk with a patent-infringement lawsuit regarding portable MP3 players. The suit was filed in Marshall, Texas; this is a common location for patent infringement suits due to speedy trials and juries that often find in favor of the plaintiff. Texas MP3 Technologies claimed infringement with U.S. patent 7,065,417, awarded in June 2006 to multimedia chip-maker SigmaTel, covering "an MPEG portable sound reproducing system and a method for reproducing sound data compressed using the MPEG method." [9]
Alcatel-Lucent also claims ownership of several patents relating to MP3 encoding and compression. In November 2006, (prior to the companies' merger) Alcatel filed a lawsuit against Microsoft (see Alcatel-Lucent v. Microsoft), alleging infringement of seven of its patents. On February 23, 2007 a San Diego court upheld the suit, and awarded Alcatel-Lucent a record-breaking $1.52bn in damages.[10] Microsoft has said it will appeal the verdict, maintaining that the federal jury's decision is "unsupported by the law or facts", since Microsoft had already paid $16m to license the technology from Fraunhofer IIS which, it claims, is "the industry-recognized rightful licensor". [11]. A week later, U.S. District Judge Rudi Brewster ruled from the bench and dismissed all of Alcatel-Lucent's MP3 claims. Alcatel-Lucent plans to appeal the ruling. [12]
In short, with Thomson, Fraunhofer IIS, Sisvel (and its US subsidiary Audio MPEG), Texas MP3 Technologies, and Alcatel-Lucent all claiming legal control of relevant MP3 patents, the legal status of MP3 remains unclear in countries that permit software patents.[edit] Alternative technologies
Main article: List of codecs
Many other lossy and lossless audio codecs exist. Among these, mp3PRO, MP3, AAC, and MP2 are all members of the same technological family as MP3 and depend on roughly similar psychoacoustic models. The Fraunhofer Gesellschaft owns many of the basic patents underlying these codecs as well, with others held by Dolby Labs, Sony, Thomson Consumer Electronics, and AT&T.
In a 2005 listening test[3] which compared the performance of the LAME MP3 encoder against more modern compression formats at 128 kbit/s, it was found that there was no statistically significant difference between the results for LAME, Ogg Vorbis, several AAC encoders and WMA. However, a test at 32 kbit/s[5], showed that MP3 was significantly worse than the more modern codecs at that lower bitrate.[edit] References
^ How MP3 Was Born by Jack Ewing BusinessWeek.com. March 5, 2007. http://www.businessweek.com/print/globalbiz/content/mar2007/gb20070305_707122.htm
^ [|Amorim, Roberto] (2003-08-03), Results of 128kbps Extension Public Listening Test
^ a b [|Mares, Sebastian] (2006–01), http://www.listening-tests.info/mf-128-1/results.htm
^ David Meares, Kaoru Watanabe & Eric Scheirer (1998–02). "Report on the MPEG-2 AAC Stereo Verification Tests" (PDF). International Organisation for Standardisation. Retrieved on 2007-03-17.
^ a b [|Amorim, Roberto] (2004-07-11), Results of Dial-up bitrate public Listening Test
^ [|Bouvigne, Gabriel] (2006-11-28), freeformat at 640 kbps and foobar2000, possibilities?
^ tunequest (2007-02-26). Big List of MP3 Patents (and supposed expiration dates).
^ Duncan (2006-01-04). MP3 patent expiration?.
^ Martyn Williams (2007-02-26). Texas MP3 Technologies claims the companies infringed its patent covering 'an MPEG portable sound reproducing system'. IDG News Service.
^ BBC report of the Alcatel-Lucent lawsuit verdict.
^ Joe Wilcox (2007-02-23). Microsoft's Patent Disputes with Alcatel-Lucent, AT&T Make Waves.
^ Anne Broache (2007-03-02). Microsoft wins in second Alcatel-Lucent patent suit. CNET News.com, published on ZDNet news.[edit] See also
Comparison of audio codecs
Copyright infringement
Digital audio player
ID3
Joint stereo
LRC (file format)
Media player
MP3 blog
MP3 Surround
Streaming Media[edit] External links
Fraunhofer IIS
The Story of MP3 - How MP3 was invented, by Fraunhofer IIS
List of relevant patents
Thompson Licensing FAQ
SanDisk MP3 seizure order overturned
Do MP3 encoders sound different?
MP3 Patents in Upheaval After Verdict (February 23, 2007, The New York Times)
Multimedia compression formats
v • d • e[hide]
Retrieved from "http://en.wikipedia.org/wiki/MP3"
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MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding, lossy compression format, and algorithm, designed to greatly ...MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding, lossy compression format, and algorithm, designed to greatly ...Download.com Music is your source for legal and free MP3 downloads. ... but we're extra proud to say we just published our 100000th song!
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Popular songs (pop songs) are songs which may be considered in between art songs and folk songs. They are usually accompanied in performance and recording by a band. They are not anonymous in origin and have known authors. They may be notated by their author(s) or transcribed after recording and may also be composed in collaboration more often than art songs, for instance by an entire band. Popular songs are often a part of individual and cultural, but seldom national, identity. Performers may not have undergone formal voice training but, in some cases, highly stylized vocal techniques are used. Many people consider songs in popular music to have in general simpler structures than art songs, however, musicologists who are "both contemptuous and condescending [of popular music] are looking for types of production, musical form, and listening which they associate with a different kind of music...'classical music'...and they generally find popular music lacking" (Middleton 1990, p.103).-
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Song
From Wikipedia, the free encyclopediaFor other uses, see Song (disambiguation).
A song is a relatively short musical composition for the human voice (commonly accompanied by other musical instruments), which generally (exceptions would be scat songs) features words (lyrics). It is typically for a solo singer, though may also be a duet, trio, or more voices (works with more than one voice to a part, however, are considered choral). The words of songs are typically of a poetic, rhyming nature, although they may be religious verses or free prose. Songs can be broadly divided into many different forms, depending on the criteria used. One division is between "art songs", "popular music songs", and "folk songs". Other common methods of classification are by purpose (sacred vs secular), by style (dance, ballad, Lieder, etc.) or by time of origin (Renaissance, Contemporary, etc).
Colloquially, song is often used to refer any music composition, even those without vocals (though in music styles that are predominantly vocal-based, a composition without vocals is often called an instrumental). In European classical music, however, this usage is considered incorrect and "song" should only be used to describe a composition for the human voice.
Cultural typesArt songs
Art songs are songs created for performance in their own right, or for the purposes of a European upper class, usually with piano accompaniment, although they can also have other types of accompaniment such as an orchestra or string quartet, and are always notated. Generally they have an identified author(s) and require voice training for acceptable performances. The German word for song, "Lied" (plural: "Lieder"), is used in French and English-speaking communities to refer to the serious art song, whereas in German-speaking communities the word "Kunstlied" (plural: "Kunstlieder") is used to distinguish art song from folk song ("Volkslied"). The lyrics are often written by a lyricist and the music separately by a composer. Art songs may be more formally complicated than popular or folk songs, though many early Lieder by the likes of Franz Schubert are in simple strophic form. They are often important to national identity. Art songs feature in many European cultures, including but not limited to: Russian (romansy), Dutch (lied), Italian (canzoni), French (m?lodies), Scandinavian (s?nger), Spanish (canciones). Cultures outside of Europe may have what they consider to be a classical music tradition, such as India, and thus feature art songs.
Of the romantic music era, the art song is considered one of the most distinctive music forms developed. The accompaniment of pieces of this period is considered as an important part of the composition. The art song of this period is often a duet in which the vocalist and accompanist share in interpretive importance. The pieces were most often written to be performed in a home setting although today the works enjoy popularity as concert pieces. The emergence of poetry during this era was much of what inspired the creation of these pieces by Brahms, Schumann, Schubert and other period composers. These composers set poems in their native language. Many works were inspired by Johann Wolfgang von Goethe and Heinrich Heine. An art song with a German text is often referred to as a Lied. The romantic art song was often reflective of the popular poetic notions of despair created by places, legends, nature or lost love. Some composers would interpret the poem literally and create music which imitated the music and imagery of the music. The vocal melody was created to reflect the form and emphasis of the poem. The mood of the piece would often be summarized in the closing piano section called a postlude. To reflect the stanzas of a poem, the composer could use strophic form to reuse music for each stanza. Another method would be to write new music for each stanza to create a unique form, this was through-composed form known in German as durchkomponiert. A combination of both of these techniques in a single setting was called a modified strophic form. Often romantic art songs sharing similar elements were grouped as a song cycle. (Kamien, 217–18)Popular songs
Popular songs (pop songs) are songs which may be considered in between art songs and folk songs. They are usually accompanied in performance and recording by a band. They are not anonymous in origin and have known authors. They may be notated by their author(s) or transcribed after recording and may also be composed in collaboration more often than art songs, for instance by an entire band. Popular songs are often a part of individual and cultural, but seldom national, identity. Performers may not have undergone formal voice training but, in some cases, highly stylized vocal techniques are used. Many people consider songs in popular music to have in general simpler structures than art songs, however, musicologists who are "both contemptuous and condescending [of popular music] are looking for types of production, musical form, and listening which they associate with a different kind of music...'classical music'...and they generally find popular music lacking" (Middleton 1990, p.103).-Song structure or how a pop song is constructed
Main article: Song structure (popular music)
Popular songs almost always have a well defined structure. The song is constructed using three to five individually distinct musical sections, which are then strung together to form the complete song.
A structural analysis of a typical pop song is in this order:
Introduction
Verse
Chorus
Verse
Chorus
Instrumental Bridge
Repeat chorus to fade
The above pop song structure is an extremely common way of building a modern pop song, including hip hop, rock songs and all other genres of pop songs. Some simple song structures have only a single section which is repeated with slight modifications in order to sustain a listener's interest in the song.
Pop songs also have rhyming schemes which are commonly used by lyricists. These are classified using capital letters of the Latin alphabet. For example, a song's verse section may have this rhyming scheme: ABAC ABAD. This means that the verse comprises of eight lines. Lines 1, 3, 5 and 7 rhyme with each other. Also, lines 2 and 6 rhyme. Whereas lines 4 and 8 do not rhyme with any lines.Folk songs
Folk songs are songs of often anonymous origin (or are public domain) that are transmitted orally. They are frequently a major aspect of national or cultural identity. Art songs often approach the status of folk songs when people forget who the author was. Folk songs are also frequently transmitted non-orally (that is, as sheet music), especially in the modern era. Folk songs exist in almost every, if not all, culture(s). For more on folk songs, see Folk music.
For a list of influential songs, see:
The Rock and Roll Hall of Fame's 500 Songs that Shaped Rock and RollOverview
The most common types of domain names are hostnames that provide more memorable names to stand in for numeric IP addresses. They allow for any service to move to a different location in the topology of the Internet (or an intranet), which would then have a different IP address.
By allowing the use of unique alphabetical addresses instead of numeric ones, domain names allow Internet users to more easily find and communicate with web sites and other server-based services. The flexibility of the domain name system allows multiple IP addresses to be assigned to a single domain name, or multiple domain names to be assigned to a single IP address. This means that one server may have multiple roles (such as hosting multiple independent Web sites), or that one role can be spread among many servers. One IP address can also be assigned to several servers, as used in anycast and hijacked IP space.
Hostnames are restricted to the ASCII letters "a" through "z" (case-insensitive), the digits "0" through "9", and the hyphen, with some other restrictions. Registrars restrict the domains to valid hostnames, since, otherwise, they would be useless. The Internationalized domain name (IDN) system has been developed to bypass the restrictions on character allowances in hostnames, making it easier for users of non-english alphabets to use the Internet. The underscore character is frequently used to ensure that a domain name is not recognized as a hostname, for example with the use of SRV records, although some older systems, such as NetBIOS did allow it. Due to confusion and other reasons, domain names with underscores in them are sometimes used where hostnames are required.
[edit] Examples
The following example illustrates the difference between a URL (Uniform Resource Locator) and a domain name:
URL: http://www.example.net/index.html
Domain name: www.example.net
Registered domain name: example.net
As a general rule, the IP address and the server name are interchangeable. For most Internet services, the server will not have any way to know which was used. However, the explosion of interest in the Web means that there are far more Web sites than servers. To accommodate this, the hypertext transfer protocol (HTTP) specifies that the client tells the server which name is being used. This way, one server with one IP address can provide different sites for different domain names. This feature goes under the name virtual hosting and is commonly used by Web hosts.
For example, as referenced in RFC 2606 (Reserved Top Level DNS Names), the server at IP address 192.0.34.166 handles all of the following sites:
example.com
www.example.com
example.net
www.example.net
example.org
www.example.org
When a request is made, the data corresponding to the hostname requested is served to the user.
[edit] Top-level domains
Every domain name ends in a top-level domain (TLD) name, which is always either one of a small list of generic names (three or more characters), or a two characters territory code based on ISO-3166 (there are few exceptions and new codes are integrated case by case). Top-level domains are sometimes also called first-level domains.The generic top-level domain (gTLD) extensions are:[show] v • d • e Generic top-level domains
Unsponsored .biz .com .edu .gov .info .int .mil .name .net .org
Sponsored .aero .cat .coop .jobs .mobi .museum .pro .tel .travel
Infrastructure .arpa .root
Startup phase .asia
Proposed .berlin .bzh .cym .gal .geo .kid .kids .mail .nyc .post .sco .web .xxx
Deleted/retired .nato
Reserved .example .invalid .localhost .test
Pseudo-domains .bitnet .csnet .local .onion .uucp
Unofficial see Alternative DNS roots
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See also: Country code top-level domains
The country code top-level domain (ccTLD) extensions are:
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See also: Generic top-level domains[edit] Other-level domains
In addition to the top-level domains, there are second-level domain (SLD) names. These are the names directly to the left of .com, .net, and the other top-level domains. As an example, in the domain en.wikipedia.org, "wikipedia" is the second-level domain.On the next level are third-level domains. These domains are immediately to the left of a second-level domain. In the en.wikipedia.org example, "en" is a third-level domain. There can be fourth and fifth level domains and so on, with virtually no limitation. An example of a working domain with five levels is www.sos.state.oh.us. Each level is separated by a dot or period symbol between them.Domains of third or higher level are also known as subdomains, though this term technically applies to a domain of any level, since even a top-level domain is a "subdomain" of the "root" domain (a "zeroth-level" domain that is designated by a dot alone).Traditionally, the second level domain was the name of the company or the name used on the internet. The third level was commonly used to designate a particular host server. Therefore, ftp.wikipedia.org might be an FTP server, www.wikipedia.org would be a World Wide Web Server, and mail.wikipedia.org could be an email server. Modern technology now allows multiple servers to serve a single subdomain, or multiple protocols or domains to be served by a single computer. Therefore, subdomains may or may not have any real purpose.
[edit] Official assignment
ICANN (Internet Corporation for Assigned Names and Numbers) has overall responsibility for managing the DNS. It controls the root domain, delegating control over each top-level domain to a domain name registry. For ccTLDs, the domain registry is typically controlled by the government of that country. ICANN has a consultation role in these domain registries but is in no position to regulate the terms and conditions of how a domain name is allocated or who allocates it in each of these country level domain registries. On the other hand, generic top-level domains (gTLDs) are governed directly under ICANN which means all terms and conditions are defined by ICANN with the cooperation of the gTLD registries.Domain names which are theoretically leased can be considered in the same way as real estate, due to a significant impact on online brand building, advertising, search engine optimization, etc.A few companies have offered low-cost, below-cost or even free domain registrations, with a variety of models adopted to recoup the costs to the provider. These usually require that domains are hosted on their site in a framework or portal, with advertising wrapped around the user's content, revenue from which allows the provider to recoup the costs. When the DNS was new, domain registrations were free. A domain owner can generally give away or sell infinite subdomains of their domain, e.g. the owner of example.edu could provide domains that are subdomains, such as foo.example.edu and foo.bar.example.edu.
[edit] Uses and abuses
As domain names became attractive to marketers, rather than just the technical audience for which they were originally intended, they began to be used in manners that in many cases did not fit in their intended structure. As originally planned, the structure of domain names followed a strict hierarchy in which the top level domain indicated the type of organization (commercial, governmental, etc.), and addresses would be nested down to third, fourth, or further levels to express complex structures, where, for instance, branches, departments, and subsidiaries of a parent organization would have addresses which were subdomains of the parent domain. Also, hostnames were intended to correspond to actual physical machines on the network, generally with only one name per machine.However, once the World Wide Web became popular, site operators frequently wished to have memorable addresses, regardless of whether they fit properly in the structure; thus, since the .com domain was the most popular and memorable, even noncommercial sites would often get addresses under it, and sites of all sorts wished to have second-level domain registrations even if they were parts of a larger entity where a logical subdomain would have made sense (e.g., abcnews.com instead of news.abc.com). A Web site found at http://www.example.org/ will often be advertised without the "http://", and in most cases can be reached by just entering "example.org" into a Web browser. In the case of a .com, the Web site can sometimes be reached by just entering "example" (depending on browser versions and configuration settings, which vary in how they interpret incomplete addresses).The popularity of domain names also led to uses which were regarded as abusive by established companies with trademark rights; this was known as cybersquatting, in which somebody took a name that resembled a trademark in order to profit from traffic to that address. To combat this, various laws and policies were enacted to allow abusive registrations to be forcibly transferred, but these were sometimes themselves abused by overzealous companies committing reverse domain hijacking against domain users who had legitimate grounds to hold their names, such as their being generic words as well as trademarks in a particular context, or their use in the context of fan or protest sites with free speech rights of their own.Laws that specifically address domain name conflicts include the Anticybersquatting Consumer Protection Act in the United States and the Trademarks Act, 1999, in India. Alternatively, domain registrants are bound by contract under the UDRP to comply with mandatory arbitration proceedings should someone challenge their ownership of the domain name.
[edit] Generic domain names — problems arising out of unregulated name selection
Within a particular top-level domain, parties are generally free to select an unallocated domain name as their own on a first come, first served basis, resulting in Harris's lament, all the good ones are taken. For generic or commonly used names, this may sometimes lead to the use of a domain name which is inaccurate or misleading. This problem can be seen with regard to the ownership or control of domain names for a generic product or service.
By way of illustration, there has been tremendous growth in the number and size of literary festivals around the world in recent years. In this context, currently a generic domain name such as literary.org is available to the first literary festival organisation which is able to obtain registration, even if the festival in question is very young or obscure. Some critics would argue that there is greater amenity in reserving such domain names for the use of, for example, a regional or umbrella grouping of festivals. Related issues may also arise in relation to non-commercial domain names.
[edit] Unconventional domain names
Due to the rarity of one-word dot-com domain names, many unconventional domain names, domain hacks, have been gaining popularity. They make use of the top-level domain as an integral part of the Web site's title. Two popular domain hack Web sites are del.icio.us and blo.gs, which spell out "delicious" and "blogs", respectively.
Unconventional domain names are also used to create unconventional email addresses. Non-working examples that spell 'James' are [email protected] and [email protected], which use the domain names m.es (of Spain's .es) and mes.com, respectively.
[edit] Commercial resale of domain names
An economic effect of the widespread usage of domain names has been the resale market (After Market) for generic domain names that has sprung up in the last decade. Certain domains, especially those related to business, gambling, pornography, and other commercially lucrative fields of digital world trade have become very much in demand to corporations and entrepreneurs due to their importance in attracting clients. The most expensive Internet domain name to date, according to Guinness World Records, is business.com which was resold in 1999 for $7.5 million, but this was $7.5 million in stock options, not in cash. Later the stock was valued at, not sold, for $2 million and may even be worth less today Newsweek [1]. There are disputes about the high values of domain names claimed and the actual prices of many sales, because value is an opinion by people.
Another high-priced domain name, sex.com, was stolen from its rightful owner by means of a forged transfer instruction via fax. During the height of the dot-com era, the domain was earning millions of dollars per month in advertising revenue from the large influx of visitors that arrived daily. Two long-running U.S. lawsuits resulted, one against the thief and one against the domain registrar VeriSign [2]. In one of the cases, Kremen v. Network Solutions, the court found in favor of the plaintiff, leading to an unprecedented ruling that classified domain names as property, granting them the same legal protections. In 1999, Microsoft traded the name Bob.com with internet entrepreneur Bob Kerstein for the name Windows2000.com which was the name of their new operating system. [3]
One of the reasons for the value of domain names is that even without advertising or marketing, they attract clients seeking services and products who simply type in the generic name. Furthermore, generic domain names such as movies.com or Books.com are extremely easy for potential customers to remember, increasing the probability that they become repeat customers or regular clients.
Although the current domain market is nowhere as strong as it was during the dot-com heyday, it remains strong and is currently experiencing solid growth again. [4] Annually tens of millions of dollars change hands due to the resale of domains. Large numbers of registered domain names lapse and are deleted each year. On average 25,000 domain names drop (are deleted) every day.Very important to remember is that a domain (name, address) must be valued separately from the web (content, revenue)that it is used for. The high prices have usually been paid for the revenue that was generated from the web at the domain's address (url.). The intrinsic value of a domain is the registration fee. There is no such a thing as a current market value for a domain: It just takes what somebody pays. The Fair Market Value of a domain can be anything from the registration fee: The lowest known past selling price, the highest known past selling, price, the most recent selling price, or just any past selling price and any of these (or any sum resp. division etc.) is usually added to the current or expected revenue from the web content (advertising, sales, etc.). Domain (name + ext.) should not be mixed with Web (content + revenue). The estimation by appraisers are always the addition of what they would like that a domain is worth together with the effective/expected/desired revenue from the web content. Some people put value on the length of the SLD (name) and other people prefer description capability, but the shorter a SLD is, the less descriptive it can be. Also, if short is crucial, then the TLD (extension) should be short too. It is less realistic to get a domain like LL.travel or LL.mobi than a domain travel.LL or mobi.LL. This illustrates the relativity of domain value estimation. It can be safely put that the revenue af a web (content) can be easily stated, but that the value of a domain (SLD.TLD aka name.ext) is a matter of opinions and preferences. In the end, however, any sale depend of the estimates by the domain seller and the domain buyer.
People who buy and sell domain names are known as domainers. People who sell value estimation services are known as appraisers.
According to Guiness Book of World Records and MSNBC, the most expensive domain name sales on record as of 2004 were: Business.com for $7.5 million in December 1999, AsSeenOnTv.com for $5.1 million in January 2000, Altavista.com for $3.3 million in August 1998, Wine.com for $2.9 million in September 1999, CreditCards.com for $2.75 million in July 2004, and Autos.com for $2.2 million in December 1999. [5]
[edit] Domain name confusion
Intercapping is often used to clarify a domain name. However, DNS is case-insensitive, and some names may be misinterpreted when converted to lowercase. For example: Who Represents, a database of artists and agents, chose whorepresents.com; a therapists' network thought therapistfinder.com looked good; and another website operating as of October 2006, is penisland.net a website for Pen Island, a site that claims to be an online pen vendor, but exists primarily as a joke, as it has no products for sale. In such situations, the proper wording can be clarified by use of hyphens. For instance, Experts Exchange, the programmers' site, for a long time used expertsexchange.com, but ultimately changed the name to experts-exchange.com.
Leo Stoller threatened to sue the owners of StealThisEmail.com on the basis that, when read as stealthisemail.com, it infringed on claimed trademark rights to the word "stealth". [6].
[edit] See also
Domaining
Domain hack
Domain tasting, also known as domain kiting
Domain name warehousing
Fully qualified domain name
ICANN
Internationalized domain name
Name generator
Uniform Resource Locator
World Wide Web
Web page
Web site
Geodomain
domains yahoo,domain name yahoo,domain registration yahoo,yahoo web hosting,free web hosting,free domain,free hosting
Finance
From Wikipedia, the free encyclopedia
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Finance
Personal finance
Questions in personal finance revolve around
How much money will be needed by an individual (or by a family) at various points in the future?
Where will this money come from (e.g. savings or borrowing)?
How can people protect themselves against unforeseen events in their lives, and risk in financial markets?
How can family assets be best transferred across generations (bequests and inheritance)?
How do taxes (tax subsidies or penalties) affect personal financial decisions?
Personal financial decisions may involve paying for education, financing durable goods such as real estate and cars, buying insurance, e.g. health and property insurance, investing and saving for retirement.
Personal financial decisions may also involve paying for a loan.
Business finance
In the case of a company, managerial finance or corporate finance is the task of providing the funds for the corporations' activities. It generally involves balancing risk and profitability. Long term funds would be provided by ownership equity and long-term credit, often in the form of bonds. These decisions lead to the company's capital structure. Short term funding or working capital is mostly provided by banks extending a line of credit.
On the bond market, borrowers package their debt in the form of bonds. The borrower receives the money it borrows by selling the bond, which includes a promise to repay the value of the bond with interest. The purchaser of a bond can resell the bond, so the actual recipient of interest payments can change over time. Bonds allow lenders to recoup the value of their loan by simply selling the bond.
Another business decision concerning finance is investment, or fund management. An investment is an acquisition of an asset in the hopes that it will maintain or increase its value. In investment management - in choosing a portfolio - one has to decide what, how much and when to invest. In doing so, one needs to
Identify relevant objectives and constraints: institution or individual - goals - time horizon - risk aversion - tax considerations
Identify the appropriate strategy: active vs passive - hedging strategy
Measure the portfolio performance
Financial management is duplicate with the financial function of the Accounting profession. However, Financial Accounting is more concerned with the reporting of historical financial information, while the financial decision is directed toward the future of the firm.
Shared Services
There is currently a move towards converging and consolidating Finance provisions into shared services within an organization. Rather than an organization having a number of separate Finance departments performing the same tasks from different locations a more centralized version can be created.
Finance of states
Country, state, county, city or municipality finance is called public finance. It is concerned with
Identification of required expenditure of a public sector entity
Source(s) of that entity's revenue
The budgeting process
Debt issuance (municipal bonds) for public works projects
Financial economics
Main article: Financial economics
Financial economics is the branch of economics studying the interrelation of financial variables, such as prices, interest rates and shares, as opposed to those concerning the real economy. Financial economics concentrates on influences of real economic variables on financial ones, in contrast to pure finance.
Financial mathematics
Main article: Financial mathematics
Financial mathematics is the main branch of applied mathematics concerned with the financial markets. Financial mathematics is the study of financial data with the tools of mathematics, mainly statistics. Such data can be movements of securities - stocks and bonds etc. - and their relations. Another large subfield is insurance mathematics.
Experimental finance
Main article: Experimental finance
The goals of experimental finance are to establish different market settings and environments to observe experimentally and analyze agents' behavior and the resulting characteristics of trading flows, information diffusion and aggregation, price setting mechanisms, and returns processes. Researchers in experimental finance can study to what extent existing financial economics theory makes valid predictions, and attempt to discover new principles on which such theory can be extended. Research may proceed by conducting trading simulations or by establishing and studying the behaviour of people in artificial competitive market-like settings