52-key Gasparini band organs are unique in two aspects: they have
seven bass notes, and they are transposing a minor third _down_.
The bass notes on the scale are E, F, G, A, A#, C, and D. They should
be tuned C#, D, E, F#, G, A, and B, and even a little bit below that
because the tuning of the A was about 435 Hz in France during the time
This peculiar way of tuning an organ does not seem to have been
understood widely, not even in Europe. To make things even more
complicated, some of the "bombardons" (reed basses) did not have
their normal speaking length; the low E and F (C# and D#) had shorter
resonators, about half the normal length. The cello pipes may have
been placed on wrong positions.
The best way to correct the problem is, in my humble opinion: make
seven new copies of reed basses! If Philip and/or others are
interested, I am willing to take measurements of the bombardon pipes
in the Utrecht museum, that has a 52-key Gasparini in its collection
that was never rebuilt.
The second best solution seems to put the cello pipes in their place as
octaves and make some new matching pipes for those that are missing or
cannot be used.
Hans van Oost, Netherlands