Vintage 1980s Yamaha DX21 Synthesizer

YAMAHA DX21 61-key polyphonic digital FM algorithm synthesizer. The DX21 is like the "baby brother" of the original DX7. It is 4-operator FM unlike the more advanced 6-operator architecture of the DX7, but has some features that the DX7 does not. One of these is both Dual and Single modes of play, which allows the player to layer two different sounds. Another is its built in Chorus effect, which the player can select ON or OFF, that gives whatever voice it is applied to a wider, fatter sound. The DX21 also allows one to split the keyboard so as to play one voice with the left hand and another with the right. The DX21 provides a full five-octave keyboard but in a much more compact form factor. That being said, it is still very solidly built with a steel (not plastic) chassis, so it's not a featherweight, but is considerably lighter than a DX7 or its 4-op sibling, the DX9. One could think of it as a more advanced DX9 in a much smaller package.