[Under construction, sharing with colleagues.]

This is an interactive simulation of the Triadex Muse invented by Marvin Minsky and Edward Fredkin in 1969. The Muse uses digital logic circuitry to implement algorithms that compose musical melodies.

Don's original article is here: Triadex Muse in JavaScript.

There is also a standalone version for the Barbican Centre exhibit that runs on a tablet.

This is a standalone version, not intended for a tablet, with some extra capabilities that I'll be adding over time.

Synchronized Muses

The Muse had a feature where, if you had more than one, you could run a cable between them, and a master Muse would synchronize the slave Muses. So we have that here. You can spawn new Muse windows, and the slaves receive the clock pulse from the master.

Try it out, here. Select the "Meditation" example above, because it a has a lot of whole notes, and spawn 2 or 3 slave Muses. Set the INTERVAL switches of the slaves to differnet values. Set the slaves to RUN. And then start the master.


Click on an example below to load it into the Muse.

Major Scale
1 Octave
Major Scale
2 Octaves, C is repeated
Major Scale
2 Octaves, split
48-note Pattern
Combining binary and divide-by-3 counters
15-note Pattern
4 bits of the shift register
240 Note Pattern
Binary counter and 4-bit shift register, 16 x 15
Michael's Tune
By (then) 8 year old Michael Fredkin
Muser's Waltz
B1 B2 on the shift register generate the 3 pattern
Dorian Scale
Adds a constant 1 for Dorian mode, D to D
Dorian Muse
A melody in the Dorian mode
Theme and Variations
From the 8-4-2-1 shift register taps
Starts So Simple
Variations on 4 notes
Ed's Rhythm Piece
By Ed Fredkin, play it fast and pretend it's drums
Marvin's Yodel
By Marvin Minsky
Rhyming Couplets
Four measures climb up, each time a different way
The Crazy Cuckoo
Playing with a 6 note down, 6 note up theme
Uses the C1/2 row to hop up an octave
Slow, lots of whole notes, so you can see what's happening


Create a slave Muse in another window, synced to this one.


The large matrix is eight 40-position slide switches that pick values from the rows, where each row is one of these binary (0, 1) outputs:

  • C1 C2 C4 C8: a 4-bit binary counter
  • C 1/2: the clock pulse
  • C3 C6: a 2-bit binary counter clocked every three beats
  • B1 - B31: a 31-bit shift register

The state of the counters is shown with blue lamps, the shift register with green.

The four INTERVAL switches are binary weighted and select the pitch in a major scale over two octaves.

The four THEME switch values are XNOR'd together to feed the shift register.