The reacTogon is a multi-touch sensitive music arpeggiator based on the harmonic table. Copyright 2007 Mark Burton
"Each hexagonal cell on the surface represents a fixed note on the harmonic table. The placement of the discs influences the whether or not a note is played, as well as its placement in the sequence. By stringing together a number of directional discs, an entire musical sequence can be created. Special discs can also initiate multiple sequences, for more complex patterns. A bank of touch-sensitive sliders are then used to change volume, timbre and rhythm of the notes."