I'm going through some old MIDI files that I got from Warren Trachtman,
and I'm a bit confused.  Some are labeled "scanImageMidiWexpression",
some are labeled "erollMidi W Expression", and others are labeled
"eRollMidi".  Does anyone know the difference between the "scan image"
and "eRolls"?

Thanks,
Skip Klosz

 [ A MIDI file is simply a 'box' which can contain files for different
 [ purposes, e.g., controlling a perforator, controlling a pneumatic
 [ player instrument (as a substitute for a paper music roll) or for
 [ playing music using a computer or a keyboard synth.  I think Warren
 [ Trachtman and others labelled the pneumatic piano files as "eRolls".
 [ -- Robbie