The Countdown to Maker Faire Bay Area is On!


Relay organ plays the sound of switching

Music Technology
Relay organ plays the sound of switching

Youtuber ffoitl shares this refreshing take on the MIDI synthesizer, utilizing the acoustic side effects of a relay switch –

a musical instrument inspired by elisha gray’s “musical telgraph” one of the first electric/electronic musical instruments ever.
it’s basically a relay oscillator than be “tuned” to various frequencies via midi controlled capacitors.
in the video i use a tenori-on as a midi sequencer. the video of the tenori-on is not totally in sync with the rest of the video but you should get an idea.
the sound is recorded with a self-built piezo contact mic and a coil taken from a solenoid.

Cited as inspiration, Elisha Gray‘s invention is acknowledged as the first electric synthesizer –


In 1876, after narrowly losing the race to patent the telephone, Gray created the first single note oscillator from a self vibrating electromagnetic circuit. The Musical Telegraph transmitted the sound of steel reed oscillations over telephone line. Anyone for a remake?

10 thoughts on “Relay organ plays the sound of switching

  1. Anonymous says:

    This reminds me of using the tape-drive-control relay in Radio Shack TRS-80 Model I to make cricket noises.

    The relay controlled turning the tape recorder on and off (the tape was used to save programs). You could open and close the relay under program control. You could change the frequency, but it usually sounded like you had a cricket in the room.

    The relays were also notoriously fragile and would die if abused (although I never had problems).

  2. says:

    I think the obvious next step is to have a series of relays each in a different sized acoustic resonator to change the pitch. Pretty sweet.

  3. anachrocomputer says:

    We did the same kind of thing with the cassette relay in the BBC Micro.

  4. Collin Cunningham says:

    A while back, a friend of mine decided to build a color organ as gift for someone. He decided to use a bunch of ‘ice cube’ relays to get the job done – and that it did, very loudly! You could hardly hear the music is was syncing to. Regretting the oversight, he was initially quite ticked off, but later came to see the sonic potential.

    anyway, I like the sound of relays.

  5. Stein-Ove Bratthammer says:

    Hi! when i was younger i had a commodore 64. I loaded a software that made the disk drive play music! a very noicy music dough.

Comments are closed.

Discuss this article with the rest of the community on our Discord server!
Maker Faire Bay Area 2023 30% off early bird ticket sales ends August 31st, 2023!

Escape to an island of imagination + innovation as Maker Faire Bay Area returns for its 15th iteration!

Prices Increase in....