There are many kinds of opera."Chamber" operas, requiring only a few singers and instrumentalist, may be only a half hour in lenght; some of the longest operas take five hours to perform and involve hundreds of singers and dancers. In most operas all the words are sung, but in some there is spoken dialogue. Some operas are primarily successions of arias connected by the declaimed type of speech-song known as recitative. In others the flow of dramatic action is not interrupted by any set piece such as an aria. Operas can be tragic or gay; superficial in meaning or deeply philosophical; witty and sophisticated in tone or restrained in passion. Musically an opera can be composed primarily of straightforward vocal melodies, with the orchestra playing the simplest kind of accompaniment, or it can be highly complex in melody and harmony, with the orchestra equal in importance to the voice. Really, then, there is no such thing as a "typical" opera.
Opera's success has been due to its composers; it has survived only because it has offered great music. The inventiveness of a long line of geniuses has continually refreshed the whole field of opera: Monteverdi, Lully, Handel, Alessandro Scarlatti, Gluck, Mozart, Rossini, Bellini, Weber, Meyerbeer, Wagner, Verdi, Mussorgsky, Strauss, Debussy, Puccini, Berg.
