This was discussed on piporg-l last year. There is an established system
(and, apparently, a large listing) that uses the up-down characteristic of
several notes following the first. Mary Had A Little Lamb would be
dduuxxdxxuux. It was said that virtually no tunes have common figures
after seven or eight notes. I have posted the group to ask about more
technical information. There is a database search engine for
piporg-l posts also, if I am unable to get a reply.

I liken this to tower bell change ringing. With each round, timing of
adjacent positions is swapped, making annotation quite simple and not
related to key or scale. Also quite simple was the suggestion that, since
piano roll data is not on the paper but due to the holes, we would be far
ahead to save the chad that is punched out and play _that_ back. Saves on
storage space too....

Rambling on further, I find no reference to the punchouts being called
"chad" before the punched card era. The punches traditionally made round
holes in Hollerith and Jacquard cards, and left bits of paper in a hopper.
Later, a punch which made u-shaped holes and bent back the loose bit of
paper rather than cutting it off was invented by Chadless. (This reminds
me of curled punchtangs on music box disks.) Thus the Chadless Punch did
not make any of those little--uh--chad?

Karl A. Petersen
Meridian, Idaho

Still without an upright Duo-Art. The trailer, piano board and dolly are
ready!