A drummer is a person who plays drums, which includes but is not limited to a drum kit ("drum set" or "trap set", including but not limited to cymbals) and accessory based hardware which includes an assortment of pedals and standing support mechanisms, marching percussion and/or any musical instrument that is struck within the context of a wide assortment of musical genres. The term percussionist applies to a musician who performs struck musical instruments of numerous diverse shapes, sizes and applications. Most contemporary western ensembles bands for Rock, Pop, Jazz, R&B etc. includes a drummer within the context of its music based ensemble for purposes including but not limited to timekeeping, and artist based applications deemed appropriate towards the elevation of a prescribed music based aesthetic. Most drummers of this particular designation work within the context of a larger contingent (aka rhythm section) that may also include, keyboard (a percussion instrument) and/or guitar, auxiliary percussion (often of non western origin) and bass (bass viol or electric). Said ensembles may also include melodic based mallet percussion including but not limited to: vibraphone, marimba and/or xylophone. The rhythm section, being the core metronomic foundation with which other melodic instruments, including voices, may present the harmonic/melodic portion of the material.
First and foremost, a drummer is a musician that performs music on the multi-percussion instrument known as the drum set, which usually consists of a bass drum (with pedal), a floor tom, tom-toms, a snare drum, hi-hats, a ride cymbal, and a crash cymbal.
In popular music, the primary function of the drummer is to "keep time" or provide a steady tempo and rhythmic foundation. However, in other musical styles, such as world, jazz, classical, and electronica, the function of a drummer is often shifted from "time keeper" to soloist, whereby the main melody becomes the rhythmic development generated by the drummer or percussionist.
There are many tools that a drummer can use for either timekeeping or soloing. These include cymbals, (i.e. china, crash, ride, splash, hi-hats, etc.) Auxiliary percussion, (i.e. bells, Latin drums, cowbells, temple blocks) and many others. Also there is a single, double, and a triple bass pedal for the bass drum.