MD4

A four-track MTR with an MD data disc as the recording medium.
MD technology made it easy to produce high-quality music with less sound quality degradation and wow and flutter (rotational distortion) than cassette tapes, which were the mainstream recording media until then.
The MD4 is also equipped with a feature that enables users to mix and record instrument sounds on top of four tracks on simultaneous playback, all while erasing the tracks on playback. This feature made it possible to produce more complex music.