The Roland MKS-20 is a digital piano-type sound module released by Roland Corporation in 1986. It is a rackmount version of the popular 1980s-era Roland RD-1000 digital piano. The RD-1000 has the exact same sound engine mounted in a musical keyboard-type MIDI controller. Both use Roland's "structured adaptive synthesis approach" to provide eight keyboard sounds, including grand piano, electric piano, harpsichord, vibraphone, and clavinet. Both have three effects units built in: stereo chorus, stereo tremolo, and a three-band equalizer with a sweepable mid-range.

A digital piano is a type of electronic keyboard instrument designed to serve primarily as an alternative to the traditional acoustic piano, both in how it feels to play and in the sound it produces. Digital pianos use either synthesized emulation or recorded samples of an acoustic piano, which are played through one or more internal loudspeakers. They also incorporate weighted keys, which recreate the feel of an acoustic piano. Some digital pianos are designed to also look like an upright or grand piano. Others may be very simple, without a stand.