Roland TR-909 to automat perkusyjny, produkowany przez firmę Roland w latach 1984–1985. Projektantem instrumentu jest Tadao Kikumoto, który wcześniej opracował także projekt modelu Roland TB-303. The device itself uses some digital and partly analogue technology to generate sound. Equipped with a step sequencer, it allows you to program rhythmic sequences in one of several ways. The drum kit made available by the TR-909, due to the fact that it is partially synthesized, can be modified within a certain range, specified for a given voice. This machine is one of the first in the world to be equipped with a MIDI interface. The TR-909, thanks to its specific sound capabilities, has almost become a cult object in the circles of contemporary electronic music creators. The music genres in which this device has been used in particular are house, trance and techno as well as acid techno.