 A 1914 Orthotonophonium in the Museum of Musical Instruments of Leipzig University | |
| Classification | Aerophone |
|---|---|
| Hornbostel–Sachs classification | 412.132 |
| Inventor(s) | Arthur von Oettingen |
| Developed | 1914 |
| Related instruments | |
| Harmonium, Reed organ | |
The Orthotonophonium is a free reed aerophone similar to a Harmonium with 72 (sometimes 53) keys per octave, that can be played all diatonic key intervals and chords using just intonation. The instrument was created in 1914 by German physicist Arthur von Oettingen to advance his theories of harmonic dualism (now knows as Riemannian theory).