"Notenrollen selbst gemacht" -- "Self-made Music Rolls" -- is the title
of the article by Reiner H. Schulte which appears in Das Mechanische
Musikinstrument for April 1998.

The author owns and operates a 25-key Wrede crank-organ which plays
rolls, but he wanted more music.  So he made the spools from a clothes
pole, with plywood flanges and a length of hexagonal steel rod, and
found a source for paper 130 mm (5.12 inch) wide.  And he assembled a
small collection of suitable MIDI files.

Schulte, who notes that he's not a computer scientist, chose to convert
the MIDI song data into a text file, so that it could be edited using a
simple text editor.  A number of different shareware programs are
available which operate on text which looks something like this:

  Delta=   0 -> (MIDI) Note-On : Pitch= 69, Velocity= 64
  Delta= 192 -> (MIDI) Note-Off: Pitch= 69, Velocity= 64
  Delta=   2 -> (MIDI) Note-On : Pitch= 72, Velocity= 75
  Delta= 188 -> (MIDI) Note-Off: Pitch= 72, Velocity= 64
  Delta=   2 -> (MIDI) Note-On : Pitch= 69, Velocity= 87
  Della=  87 -> (MIDI) Note-Off: Pitch= 26, Velocity= 64

Then he used the old-time Basic programming language (still around
as 'Qbasic' in the older versions of MS-DOS) to write a program which
converts the ASCII-MIDI data into printer control commands.  The result
is a printed template, which is then punched with a little frame punch
he built of wood.  For simplicity the punch stays centered in the
wooden support, while the paper is moved underneath it, both laterally
and longitudinally.

One song can amount to 3000 to 6000 holes, nonetheless Schulte has
already punched 12 titles on two rolls, and he proudly says that they
are well received by his audiences.  In the future he would like to
modify a printer to punch the holes directly, but he says there remain
considerable mechanical tasks before that happens.  Until then, he is
sure to develop an iron fist from operating the little punch !

Robbie Rhodes