via this auction via analogsd
"This very unique machine is regarded by some as the first digital musical instrument. Designed by Edward Fredkin and Marvin Minsky at MIT, the Muse is an algorithmic music generator: it uses digital logic circuits to produce a sequence of notes based on the settings of various parameters.
Since the Muse was designed as a composition tool, not a synthesizer, there is no control over the timbre of the sound; rather, the front panel controls affect the melodies that are generated.
The four small sliders in the lower-left control Volume, Tempo, Pitch, and Fine Pitch. The switches to either side are used to start and stop the sequence, or to step through it note-by-note.
Of the eight larger sliders on the right, four control the musical intervals used (labeled A, B, C, and D), and four control the theme (labeled W, X, Y, and Z). A rest can be substituted for the lowest note by flipping a toggle switch. The exact logic behind the composition engine is rather technical, and not exactly intuitive.
The tempo clock can be slaved to that of another Muse, allowing for multi-part compositions.
It is not known exactly how many Muses were made, but they are very rare, and were not available in stores."
