The Roland TR-909 Rhythm Composer is a drum machine introduced by the Roland Corporation in 1983. It was the first Roland drum machine to use samples (for its cymbal and hi-hat sounds) alongside analog sounds. Designed by Tadao Kikumoto, who also designed the Roland TB-303 synthesizer, the 909 features a 16-step step sequencer and drum sounds that aimed for realism and cost-effectiveness. It is fully programmable, and like its predecessor, the TR-808, it can store entire songs with multiple sections, as opposed to simply storing patterns. It was the first MIDI-equipped drum machine. Around 10,000 units were produced.
This drum machine is part of the technical rider by Jeff Mills.