A drum machine is an electronic musical instrument designed to imitate the sound of drums or other percussion instruments. They are used in a variety of musical genres, not just purely electronic music. They are also a common necessity when session drummers are not available or desired.

Most modern drum machines are sequencers with a sample playback (rompler) or synthesizer component that specializes in the reproduction of drum timbres. Though features vary from model to model, many modern drum machines can also produce unique sounds, and allow the user to compose unique drum beats.

In 1930–32, the spectacularly innovative and hard to use Rhythmicon was realized by Leon Theremin at the request of Henry Cowell, who wanted an instrument with which to play compositions whose multiple rhythmic patterns, based on the overtone series, 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 preprogrammed rhythms such as mambo, tango, or the like. They also have other patterns like bossa nova

Alex Metric (born Alex Drury) is a British musician, DJ and producer. He has released numerous EPs, remixed artists such as Depeche Mode, La Roux, NERD, Phoenix, and Bloc Party as well as working as a producer for acts such as The Infadels, Charli XCX and Adam Freeland.

Alex Metric started out as a nuskoolbreaks producer and came to prominence in 2008 after being voted 'Best Breakthrough Producer' at Breakspoll. He also got voted 'Best Remixer of the Year' by London radio station XFM. In 2009, Metric joined Radio 1's 'In New DJs We Trust' with his first show on June 12, 2009. Metric quit the station at the end of 2010 to concentrate on his productions. In January 2010 Clash Music magazine ranked him at number two in their list of the best DJs of 2010, second only to Brodinski. 2011 saw the release of his collaboration with Steve Angello "open Your Eyes" on Virgin / Positive which stayed on the BBC Radio 1 A list for 4 weeks. A compilation of Alex Metric's remix & production work also titled "Open Your Eyes" was released on August 22, 2011. During the past four years he has remixed high profile bands like La Roux, Gorillaz, U2, Depeche Mode, and the Beastie Boys.