Autoharps. I remember my fifth grade teacher, Mrs. Trautman, pulling out her autoharp while we sang “What did Delaware?” I have two of them in my office now, both in need of repair (as you can see). The charm of the autoharp lies in its ability to tune every string (like all zithers) and in its ease of playability (as opposed to zithers, at least large ones). The trick is deriving a tuning from my superset of 33 just intonation pitches that allows each of the chord buttons to create usable, beautiful harmony. The tuning will have to wait until I get a long gooseneck tuning wrench. For now, here’s what I’ve come up with for the two ‘harps:
1/1, 33/32, 143/128, 147/128, 5/4, 21/16, 11/8, 3/2, 49/32, 13/8, 7/4, 121/64
1/1, 17/16, 69/64, 19/16, 39/32, 87/64, 23/16, 3/2, 203/128, 13/8, 29/16, 31/16
This leads to some pretty exotic harmony. Press the “C Maj” button on the first autoharp and get 1/1, 5/4, 3/2, a familiar, beautiful 4:5:6 structure. But press the “A Sev” on the second autoharp and you wind up with 13/8, 17/16, 39/32, 3/2 – 26:34:39:48 – also beautiful but not at all familiar. I might also decide to have some pitches differ in higher octaves, but that will have to wait until I can experiment further.