Talk about timing!  In yesterday's MMD Bing Gibbs asks about the
height of 88-note tracker bar holes.  That information was just
published in the most recent AMICA Bulletin (v. 34, no. 6 (Nov.-Dec.
1997), p.  406).  If AMICA editor Robin Pratt (and AMICA Honorary
Larry Givens, who submitted the information) doesn't mind, I'll quote
the article:


MUSIC ROLL STANDARDS, adopted at a trade convention in Chicago on
  February 13th, 1911.

 * Perforations shall be spaced nine to the inch.

 * Paper shall be 11 1/4 inches wide.

 * Music notes to be centered on the paper.

 * The distance from the inside of the flange on the drive spool end
to the base of its socket shall be 5/16".

 * The socket on the drive spool end shall be centered and have an
inside diameter of 7/16".

 * Width of the slot in the drive and socket shall be not less than
1/8", and depth of the slot not less than 1/4".

 * The tempo shall be such that when at 70, seven feet of paper pass
over the tracker bar per minute; eight feet at tempo 80, and so on.

 * Perforations along margins are recommended to be the same size
as the music perforations, and the sustaining pedal perforation
to be the third perforation from the last playing note on the bass
end of the sheet.

 * Length of shortest bridge between playing notes (repeating) to be
not less than .110".

 * The diameter of the smallest perforation to be not less than .0595".

 * The length of the smallest perforation in a music roll shall not
be less than .083" when the width does not exceed .060", or if the
width of the perforation be greater than .060", then its length shall
not be less than is sufficient to give an area of the perforation
equivalent to that of a perforation .0595" in width by .083" in length.

 * The maximum vertical diameter of the orifices of the tracker bar
for speaking pneumatics shall not exceed .089".

 --- end of quote ---

This should warm the hearts of Robbie, Craig, and other engineers here.

Matthew Caulfield

 [ Hmmm...  Possibly Baldwin exerted some 'influence' on the
 [ standard, so that their unusually high tracker bar hole would
 [ remain within spec at .089".  What t.b. height was the rest
 [ of the industry using then?  -- Robbie