rototom

right|thumb|Rototom on a standard mounting bar

The rototom is a shell-less drum developed by Al Payson and Michael Colgrass that is able to change pitch by rotating its drumhead around a threaded metal ring. Unlike many types of drums, rototoms are designed to have a variable definite pitch leading composers to write specific notes for them as pitched percussion instruments. They are also often used to extend the tom range of a standard drum kit.