The snare drum has two heads, made of either skin or plastic. The heads are stretched with great tension over the drum's metallic, circular frame. The top side is hit with drumsticks, thus aptly dubbed the batter-head. The bottom head has snares, or wires, made of gut or metal stretched rigidly across it. The snares produce a shrill rattling sound as they vibrate against the head. Accordingly, the snare drum is untuned, since it does not vary in pitch. Seven to nine snare drums may appear in a drumline.
Like the snare drum, the tenor drum evolved from the field drum of the 15th and 16th centuries. Also like the snare drum, the tenor drum - or tom-tom - is played on a horizontal plane, with the heads on the top and bottom. However, the tenor drum lacks a snare and frequently has a wooden casing. These characteristics give the drum a warmer and more hollow tone. Drumlines will link tom-toms together, with one player carrying three to six at a time. Up to five tenor drum players serve in the average drumline.
The bass drum is the largest two-headed drum in the percussion section. It is played on its side, so can be struck on either head. Moreover, its size and tone require a large, cushioned mallet to strike the heads. This beating instrument provides the drum with the thunderous tone that is its trademark. Outdoor marching units can field ten bass drums.
Large plates of brass or bronze, cymbals have a sunken, incurving shape that allows for extended vibration when the plates are struck together. This works best when leather handstraps are fastened to the plates. The tone of any given set of cymbals is fixed, but since they come in many different sizes a band leader can find the tone, if willing to shop around. The largest marching ensembles boast nine or ten cymbal players.
Also called the front line, the pit is the stationary element of the drum line. Often looking like a large jazz combo, a pit can consist of drum sets, electric guitars and basses, xylophones and vibraphones, synthesizers and electric keyboards. Pits are most often found in university marching bands, summer drum corps and high schools with generous budgets.