Yamaha PSR 520 61-key digital keyboard and arranger. The PSR-520 works by allowing the user to select a voice or style, and then play the keyboard to produce the desired sound. The keyboard also has a range of effects, such as reverb, chorus, and delay, which can be used to further customize the sound. The built-in sequencer allows users to record and playback their own compositions. The MIDI interface allows the keyboard to be connected to other MIDI devices, such as computers, synthesizers, and drum machines.