Drum
Construction
Drums with cylindrical shells can be open at one end (as is the case with timbales), or can have two drum heads, one head on each end. Single-headed drums typically consist of a skin stretched over an enclosed space, or over one of the ends of a hollow vessel. Drums with two heads covering both ends of a cylindrical shell often have a small hole somewhat halfway between the two heads; the shell forms a resonating chamber for the resulting sound. Exceptions include the African slit drum, also known as a log drum as it is made from a hollowed-out tree trunk, and the Caribbean steel drum, made from a metal barrel. Drums with two heads can also have a set of wires, called snares, held across the bottom head, top head, or both heads, hence the name snare drum. On some drums with two heads, a hole or bass reflex port may be cut or installed onto one head, as with some 2010s era bass drums in rock music.
Drum-7