A tape-based sample playback synthesizer similar in concept to the Mellotron. Dave Biro developed the instrument in the early 1970s (with funding from, among others, Rick Wakeman), as an attempt to overcome some of the limitations and reliability problems of the Mellotron. Instead of the strips of tape used in the Mellotron, the Birotron used commercially available 8-track cartrides, which contained continuous loops of tape. The Birotron was capable of reproducing up to four stereo instrument sounds per set of cartridges, as opposed to the 3-track mono capability of most Mellotron models.