snare drum

The snare drum or side drum is a widely used unpitched percussion instrument. It is often used in orchestras, marching bands and concert bands, drum corps and many other applications.
It is the center of the drum kit, the most prominent drum in most marching and stage bands, and the instrument that students of both orchestral and kit drumming learn to play first.
The snare drum is almost always double-headed, with rattles (called snares) of gut, metal wire or synthetics stretched across one or both heads. There are three patterns:

• In all but a few applications, a single set of snares is applied to the bottom of the bottom (unplayed) head. Orchestral and drum kit players use extremely thin, specialised snare drum heads, far too light to be played directly, for this bottom head.
• Pipe band side drums have a second set of snares on the bottom (inside) of the top (played or batter) head, as well as a set on the bottom of the bottom head.
• The caixa de guerra ("war box") and tarol are Latin American snare drums with a single set of snares on the top of the top head. A few of these drums omit the bottom head.

Different types can be found, like piccolo snares, that have a smaller depth for a higher pitch, rope-tuned snares (maracatu snare), and the Brazilian tarol, which commonly has snares on the top of the upper drumhead.
Historically, snare drums have been used in military and parading contexts to produce drum cadences. Today in popular music, especially with rock drum kits, the snare drum is typically used to play a backbeat pattern.