For my 1998 flyer of BluesTone roll recuts I created a chart which
showed exactly how the tracker bar layouts differ for Ampico, Duo-Art,
Welte, Automatic, and standard 88-note roll players.  It also shows
exactly which piano notes are played by each system.  I have recently
put an updated version of this tracker bar comparison chart on my
BluesTone web page, specifically at:

  http://www.bluesrolls.com/BT_TrackerBars.html

I think this will help answer Jim Moore's questions about which
channels are used for what, although I'm not sure if it's exactly
what he's looking for.  Keep in mind I chose common channel designation
numbers which I believe are standard; I based it on the Ampico "B"
amplifier being considered channel 0, for instance, and you can take
it from there.  (Note that Reblitz' "Treasures of Mechanical Music"
book renumbers most tracker bars from channel 1, since no comparisons
are being made there).  I didn't make any attempt to explain how any of
the systems actually work; I leave that to the usual reference books.

Regards,
Rob DeLand - BluesTone Music Rolls
http://www.bluesrolls.com/

 [ I concur that channel numbers 0 through 99 be used to refer to all
 [ the possible hole positions of the 9 holes-per-inch music roll.
 [ This is the viewpoint of the roll perforator, without regard to the
 [ the specific use of the music roll.  Additional mapping tables can
 [ relate the perforation location to the specific player piano system;
 [ see, for example, http://mmd.foxtail.com/Tech/Scales/Coinola-O.html
 [ -- Robbie