Hi, This subject has came up many times, so here is a system I have
been playing with.
Many rolls have been copied over the years, copies of copies, master
rolls slipping a bit, so many old 88 note rolls are not quite in time
with the original master anymore. It's sort of like copying a photocopy
again and again: the errors become worse with each successive generation.
The original sequence is still present in a roll, but the timing is
off. Pneumatic readers do work, but the result is sometimes out of
time, and require much hand editing to get the file correct again.
Timing is everything, be it a MIDI file or a roll. An arrangement
recorded in eighth triplets will sound awful if timed in simple
eighths, for example.
What I am doing here, is extracting the note information, determining
what the original beat was, 4/4, 2/4, etc., then moving everything to
an exact set musical time: the MIDI grid. Most old rolls, if compared
to a musical graph, the timing errors become readily apparent. These
errors are almost imperceptible to the ear, but are there. You would
not believe how some of the QRS MIDI files really come alive if
I built a pneumatic reader "playing" a MIDI strip, but I will not copy
the rolls in real time. The reader is connected to the input of the
step piano, and quantized by slowly rolling through the roll, one bar
at a time. In a word, treated like it was a new arrangement, copying
the note information only. The step piano will not record a note,
unless I give it command to do so, and like my own arrangements, I have
precise control over the start times and duration.
The result is a very nice looking MIDI file, on the measures, and
sounds much more snappy that the original roll did. In My view, this
corrects the timing errors that may have happened over the years, and
will make a much more accurate control file for reissuing the roll.
It is also much easier to prepare the file for use in a MIDI operated
orchestration or band organ since it is on the measures, and drum
tracks can be added -- in time. Lyrics can also be added to the file
It takes about two hours to remaster an average roll using this method.
However, I will have to soon add a belt driven Ampico/Duo-Art type
pump, with a motor capable of running for several hours without
overheating. The cheap suction box I am currently using overheats
quickly, due to the reader stack being tight.
Tempola Music Rolls
[ Editor's note:
[ Well, I don't agree that pneumatic systems inherently produce sloppy
[ timing, Andy. Have you ever examined old QRS rolls transcribed by
[ Custom Music Rolls? The disk files and the recut rolls produced by
[ Richard Tonnesen's pneumatic system replicate the old roll to plus
[ or minus 0.022 inch, which is a 32nd note in 4/4 time at MM=120, or
[ 35 milliseconds.
[ When a simple phase-locked loop is added to the process the output
[ file or music roll is an exact copy. Wayne Stahnke created preci-
[ sion transcriptions for 20 years using a pneumatic system. Very
[ little clean-up editing is needed, and that's correcting the errors
[ which are present in the original roll.
[ The pneumatic roll reader is capable of excellent precision:
[ you just have to pay attention to details, that's all, just
[ like building and maintaining a fine player piano!
[ -- Robbie