We have a had a few little cassette based devices over the last couple of years, this polyphonic cassette based mellotron caused an uproar in our chat room last year.
The OM-1 Cassette Synthesizer takes cues from instruments like the Mellotron and the Ondes Martenot but because it is built around a standard cassette tape it can sound completely unique.
When a continuous tone/note is recorded to tape, its pitch will change when the tape's playback speed is increased or decreased, in order to play notes on the device, one must individually tune each note on the knobs above each button.
The volume of the notes can be articulated by using the pressure sensitive volume control point on the lefthand side. In a similar way to Onde Martenot. You get three positions of attack/release settings.
The OM-1 also has a CV/Gate input that allows control over the cassette's pitch and volume from a linear (non quantized) voltage sequencer.
The Onde Magnetique is designed for experimentation, so we're not expecting people to start playing full symphonies on this thing, but as a fun device we think this is great. They are also hand made, so we imagine you won't find this on your high street synth store.