tremolo

Quickly alternating (oscillating) loud and quiet sounds.

drum roll

Fast, almost continuous sound on a snare drum.

vibrato

Quickly alternating slight movements up and down in pitch  on a single note.

glissando

Sliding sounds from one note to another. This is called portamento on a synthesizer

spiccato

Using the bouncing motion of the bow of a bowed stringed instrument to obtained the sound.  A type of staccato.

trill

Principal note, note above, principal note repeated and following in quick succession.  This effect is often used in slow movements of Baroque compositions.

muted brass

Various types of mutes can be used in the bell of brass instruments to change the tone. e.g. the Harman mute or wa-wa mute.

pizzicato

Plucking the strings of a normally bowed string instrument such as a violin.

muted strings

The mute is clipped to the bridge of a bowed stringed instrument to reduce the dynamic in a very quiet section.  there is not significant change in the timbre of the instrument.

walking bass

A melodic bass line described as a Walking bass in jazz and some pop styles such as Reggae.

bass pedal

A sustained bass note with moving harmonies above it.  An effect used mainly in Baroque organ music but is also used in other Baroque genres and other styles.

rubato

Holding back and pushing on the melody a little within the bar.  This is an effect used mainly in Romantic style music especially piano and vocal styles.