Steve Goode asked about repairing rolls using the information from a
MIDI file.  I just bought a re-cut roll at auction.  The recutter's
perforator must have had a few sticky punches, because throughout the
roll the same few notes were missing or only partially perforated.
Luckily, Terry Smythe has scanned this roll and made the MIDI file
available on his website (Thank you, Terry!).

I found a free MIDI app for Android tablets that has a piano-roll
style display of the notes as they are playing ("MIDI Melody & Digital
Piano", by Music Art Studio).  The app allows the display to be zoomed
incrementally to adjust the length of the notes on the screen.

So I just zoomed the display until the notes were the same size as
the properly-punched notes on the roll, and used an engineer's scale
to measure where the missing notes were relative to adjacent notes,
and transferred the measurements to the roll paper.  (This works for
the lengthwise positions of the perforations; the side-to-side positions
have to be laid out at the standard nine-to-the-inch spacing.)  I cut
out the missing holes with a wallpaper knife, and the results were
entirely satisfactory.

I also had an old roll where the leader and the first few notes (so
I thought) were missing.  Again, I was fortunate to find a MIDI file
of the roll.  After listening to the MIDI file I realized that the
first twenty or so bars of the song were gone.  The above method
would not work with that much paper missing (but I really liked the
roll) so I used the program MIDICSV.exe (available out on the Internet)
to translate the MIDI file to a CSV (comma delimited text) file,
imported the CSV file into Excel, and edited and sorted the data
down to a bunch of point coordinates.

I dumped the coordinates into an AutoCAD drawing, and drew wide
polylines representing the perforations.  I was able to plot this
at full scale on a long sheet of paper, trim it to size, cut out the
notes, and splice it onto the original roll.  It plays seamlessly.
(This process is probably more valuable as a cold winter day's
entertainment than as a practical way to make piano rolls, but at least
it is possible to re-create part of the roll.)

I will be glad to provide more details.  Contact me off list if
interested.

Bill Luecht
bill.luecht@aes.com.geentroep [delete ".geentroep" to reply]