I visited a laser cutting shop 20 years ago and I'm sure the technology
used today is probably light years ahead of what they were doing then.

This shop was making the intricate "gingerbread" decorative wood pieces
for Victorian doll houses as one of their products.  They cut the stacked
wood pieces by using a beryllium copper mask.  Beryllium copper is
reflective to laser light so wherever the mask covered nothing was cut.

The wood pieces were laid flat on the cutting table, the mask was
placed on top of the wood pieces and the laser beam was run back and
forth across the stack.  This produced very finely detailed wood pieces.

You could cut music rolls by using the same method.  Make a beryllium
copper mask that looks like a flat tracker bar with 100 holes in it.
Then make beryllium copper shutters with a hole in them the size of the
corresponding hole in the mask.  The shutters would be operated by
solenoids much the same way as the interposers are on conventional
perforators.  When the computer tells the solenoid to open a hole the
laser travels across the mask and burns all open holes.

The perforator would be constructed much the same as a conventional one
with stepped paper advance.  This method would probably be faster than
stopping the laser over each hole and burning it.

Don't get me wrong, I'm not suggesting that anyone use this method to
make music rolls since a conventional perforator would be cheaper to
build and operate.  Just thought that I'd add another idea to the
discussion.

Michael Swanson