by Bob Lewis » Sun Oct 25, 2009 9:32 am
30-32 strings is a good number to do a four key, decatonic autoharp. That is a 10 tone scale, no doubled note setup. The four keys of F, C, G, and D will be compatible with available strings. The scale is C, C#, D, E, F, F#, G, A, A#, B (no D# or G#). The bass notes are FGCDEFGAB.
This is the standard note array for the No. 6:
1 F
2 G
3 C
4 D
5 E
6 F
7 G
8 A
9 B
10 C
11 C#
12 D
13 E
14 F
15 F#
16 G
17 A
18 A#
19 B
20 C
21 C#
22 D
23 E
24 F
25 F#
26 G
27 A
28 A#
29 B
30 C
31 C#
32 D
That is already exactly what would work well but would require at least 13-14 bars to employ all the notes and support all the keys. The alternative is to support mostly F and C, using the extra F# and C# notes only for D7 and A7 bars respectively. The single harmonic minor key would then Dm (i-iv-V7 or Dm-Gm-A7).
A custom string set spec is available. Strings 1-6 would fit from standard model A or Zimmerman #73. The remaining wound strings would be out of odd/even sequence and should be custom made to get the right loop end offset length. That would place the loop ends in the correct row of end pins.
Good luck.