The Moog model 2090 Micromoog is a monophonic analog synthesizer produced by Moog Music from 1975 to 1979. During 1973 and 1974, Moog attempted to produce a synth system, possibly as a result of seeing Yamaha's massive GX-1. The bass and polyphonic components of the "Constellation" became the Taurus and Polymoog, respectively, and while the Lyra monophonic lead synth never went into production, the smaller MicroMoog emerged, using some of the ideas and technology. The Micromoog has an audio input allowing external audio to be run through the filter and VCA.