[ Ref. 201223 MMD, "O" Roll Tracker Bar Layout ]

One of my best friends and I have argued for years about the Coinola
"O" roll playing piano made by the Operators Piano Company of Chicago.
We both have concluded that the early "O" roll Coinola Model X used a
single stroke wood block that was later changed to a reiterating wood
block.

The expression holes number 15 and 16 operated a small device that
lowered the vacuum to the snare drum in later machines and in the early
machines operated a softening device for the tympani beaters by moving
the beaters closer to the head of the bass drum as well as the vacuum
decrease for the snare drum.

The music of the Capital "O" roll is considered to be some of the best
arrangements on an American coin piano roll. The piano portion of the
roll plays more piano notes than some other orchestrion rolls, enabling
enough notes for a nice piano accompaniment while the solo instruments
play actual solos and not just the same notes as the piano would
typically play.

We both agreed that most of the homemade orchestrions made in the past
fifty years do not do the "O" roll music justice compared to an
original Coinola.

Don Teach
Shreveport, Louisiana