In 061017 MMDigest Frank Metzger asked for any method to read organ
barrels and to transcribe the result by computer into a written musical
manuscript.

I can suggest a most helpful method which I used to reconstruct the
scale of a Black Forest organ clock from about 1850 (or earlier) from
the existing pinned barrel.  On this clock all but three pipes, as well
as all the claves, were missing.  The only way to rebuild the pipes was
first to find out the scale and the correct position of the pipes from
any one of the seven tracks pinned on the barrel.

In order to solve the problem I designed and built a "barrel scanner".
The scanner consists of four main parts:

A. Mechanics
1. The adjustable barrel holder (for barrels up to 550 mm length
   and up to 200 mm diameter);
2. The adjustable electrical barrel drive (up to 2 turns per minute);
3. The keyframe with up to 36 adjustable keys (claves), each one
   controlling a mechanical microswitch.

B. Electronics and software
4. The MIDI converter to convert the switch signals to MIDI;
5. The MIDI to USB converter;
6. The Apple Macintosh computer;
7. The software 'Finale PrintMusic' from MakeMusic Inc.

I finished the prototype of this scanner at the beginning of 2006.
The software transcribes the MIDI signals from the scanner into
sheet music as well as into an audio file.  Both together gave me
very successful support in finding the correct scale and position
of the notes from the existing pinned barrel.

The scanner in combination with the software works very well for
amateur use (an amateur as I am).  A minor problem comes from the
non-sufficient stability of the key and microswitch assembly.
For further use I will redesign this part of the scanner.

I ask Frank Metzger to transfer this email to Dr. Helmut Kowar.
I am open to share my knowledge with him.

Christian Greinacher
Germany