Chord organ is very simple:
- Chord = choose the chord shape; minor, major, seventh etc. Shapes can be defined by editing a text file on the SD Card (see below). Chords can have up to 8 notes.
- Root = choose the root note, in semitones from C-2 to C+2
- Waveform = push to select one of four waveforms: Sine, Square, Sawtooth and weird-gnarly-pulse-an-octave-below.
- Chord + Root CV inputs. The Root CV input is NOT volt/octave, but the output notes are perfectly in standard tuning (A = 440hz).
- Trig = Trigger output, which pulses every time the chord changes
- Out = Audio output
Here’s what developer Tom Whitwell has to say about Chord Organ:
The inspiration for Chord Organ came a few months ago, while walking home from work. It was sitting outside a house with some unwanted toys and a sign saying ‘Please take’.
It’s a Bontempi Chord Organ, a super-cheap Italian-made plastic organ, probably from the 1970s. A noisy mains-powered fan blows air through reeds, with eight chord buttons on the left. It sounds great, in an out-of-tune way.
There’s a long history of press-button-to-get-chord instruments; accordions, the Suzuki Omnichord, the Autoharp, or all those auto-accompaniment electronic keyboards that you used to see.
It’s perfectly possible to create chords on a modular synth, but it’s a pain in the arse?—?lots of tuning and messing about. I wanted something as simple as a Bontempi organ.
Here’s an example of the chord organ in action:
Pricing and Availability
There are several options for getting the Chord Organ. You can download the software (hex file) and update an existing Radio Music module, you can buy a new panel buy a new panel for $13.36, or a full Chord Organ Kit for $68.50.