Mike Knudsen said:

> I agree with everything said so far about the proposal to build
> a calliope scaled down to 20 or so notes...

Mike is, himself, an arranger/composer of 31-note music.

> So, I strongly recommend a 20er, 26er, or 31er scale, suitably
> transposed to the instrument's pipe sizes.

Thanks for mentioning transposition, Mike.  You have a choice of
musically transposing tunes on existing rolls for small organs down
to the standard "standard" calliope range simply by connecting each
hole in the tracker bar to a pipe pitched a tone, or two, or a octave
or more below that specified as "standard" for the small organ.

On the other hand,

> By pitching the instrument higher, the pipes will all be smaller,
> though the sound will not be as full and mellow.  That's another
> tradeoff to think about -- smaller pipes, but more of them (more
> notes).

Good point, Mike.

Wallace Venable