Yamaha DX21 Digital Programmable Algorithm Synthesizer

The Yamaha DX21 is a digital programmable algorithm synthesizer. It features a 61-key keyboard and offers a range of sound synthesis capabilities. The synthesizer includes controls for pitch, modulation, and volume. It has a display screen for navigating settings and parameters. The DX21 supports various performance modes and sound adjustments, including options for sustain, portamento, and different algorithms. It also has input and output ports.