Suspended cymbal

The percussion section is one of the main divisions of the orchestra and the concert band. It includes most percussion instruments and all unpitched instruments.

The percussion section is itself divided into three subsections:

A crash cymbal is a type of cymbal that produces a loud, sharp "crash" and is used mainly for occasional accents, as opposed to a ride cymbal. It can be mounted on a stand and played with a drum stick, or by hand in pairs. One or two crash cymbals are a standard part of a drum kit. Suspended crash cymbals are also used in bands and orchestras, either played with a drumstick or rolled with a pair of mallets to produce a slower, swelling crash. Sometimes a drummer may hit two different crash cymbals in a kit at the same time to produce a very loud accent, usually in rock music.

Although crash cymbals range in thickness from paper-thin to very heavy, all crash cymbals have a fairly thin edge. They are typically 14 to 18 inches (36 to 46 cm) in diameter, but sizes down to 8 inches (20 cm) and up to 24 inches (61 cm) are manufactured. Custom crash cymbals up to 28 inches (71 cm) in diameter have been used by big bands. Different thicknesses are used for different kinds of music, and the alloy for each manufacturer's models varies. A thick cymbal is likely to be used by a metal or rock band, while thinner cymbals are generally used in lighter rock. Darker crashes are best used for jazz.

In musical composition, a sound mass or sound collective is the result of compositional techniques, in which "the importance of individual pitches" is minimized "in preference for texture, timbre, and dynamics as primary shapers of gesture and impact", obscuring "the boundary between sound and noise".

Techniques which may create or be used with sound mass include extended techniques such as muted brass or strings, flutter tonguing, wide vibrato, extreme ranges, and glissandos as the continuum for "sound mass" moves from simultaneously sounding notes – clusters etc., towards stochastic cloud textures, and 'mass structure' compositional textures which evolve over time. In a sound mass, "the traditional concept of 'chord' or vertical 'event' [is] replaced by a shifting, iridescent fabric of sound".