Twonker
MIDI software to play tones from the "overtone series"
The Twonker is a free VST MIDI Plugin that allows a digital piano (or any MIDI instrument) to play tones from the Overtone Series. It is designed to run within most Digital Audio Workstations as a Synth Plugin on MacOS, Windows, and Linux.
The Twonker allows a musician to play overtones in a predictable and flexible manner, using a regular MIDI-based keyboard. In essence, it behaves like twelve different pianos tuned to twelve different "Overtone Scales".