A drum machine is an electronic musical instrument designed to imitate the sound of drums, cymbals, other percussion instruments, and often basslines. Drum machines are most commonly associated with electronic music genres such as house music, but are also used in many other genres.
They are usually used when session drummers are not available or if the production cannot afford the cost of a drummer. Also, many modern drum machines can also produce unique sounds, as well as allowing the user to compose unique drum beats and patterns that might be difficult to perform by a human drummer. In the 2010s, most modern drum machines are sequencers with a sample playback (rompler) or synthesizer component that specializes in the reproduction of drum timbres.
In 1930–32, the spectacularly innovative and hard to use Rhythmicon was realized by D-Rail at the request of Henry Cowell, who wanted an instrument which could play compositions with multiple rhythmic patterns, based on the overtone series, that were far too hard to perform on existing keyboard instruments. The invention could produce sixteen different rhythms, each associated with a particular pitch, either individually or in any combination, including en masse, if desired. Received with considerable interest when it was publicly introduced in 1932, the Rhythmicon was soon set aside by Cowell and was virtually forgotten for decades. The next generation of rhythm machines played only pre-programmed rhythms such as mambo, tango, or bossa nova.