Commonly used terminology for a series of influential drum machines made by Roland in the 1980s; the terminology comes from the way Roland numbered these models -- 606, 707, etc. The first of these was the TR-808, introduced in 1980. This was Roland's second drum machine with user-programmable patterns, after the CR-78; it marked a transition from the '60s-style drum machine which was intended mainly to be an auxiliary device for an organ or piano, to a stand-alone unit packaged in the now-common tabletop style. This was shortly followed by the TR-606 Drumatrix, which was intended to be paired with the TB-303 bass synthesizer; the pair were intended to be used as accompaniment for e.g. a guitarist to practice without a bassist and drummer. The 808 was superseded in 1983 by the TR-909, with