S. K. Goodman asked:

> I wanted to know if anyone has had negative experiences of torn rolls
> or tracking problems with the Aeolian left-ear-only tracking system?

I can't answer that question, but you may be interested in a single ear
tracking system which I installed on my pedal-electric Duo-Art.

Most of my piano rolls are original, many with damaged edges, accordion
pleats, etc.  On my Duo-Art with the four-hole tracking system many of
these older rolls would simply not track.  I finally decided to convert
the system to a single ear tracking system (the original system can
easily be reinstated).  My single ear tracking is different than the
original Aeolian in the following ways:

The ear is on the right side, mounted on the tracker bar, and is about
3/4-inch in length.  This works well because most of the edge damage on
rolls appears to be on the left hand edge.  The extra large ear allows
many gaps or tears on the roll edge to be bridged during play.  During
rewind the ear/trackerbar moves to the right, out of contact with the
roll edge.

Perhaps most important of all, the single ear tracker is fitted with
a lever to allow quick manual adjustment before a roll is played.  This
allows me to cope with extra wide, extra narrow, stretched or mis-
punched rolls.  The system has been in place about 15 years.  I have
not yet come across a roll which will not track, easily and without
damage.

There is one downside to the system, however: it only works well with
electric playing.  The balanced forces in the tracker mechanism, i.e.,
the bellows and spring, require a fairly constant vacuum -- something
unavailable in foot playing.

If anyone is interested in more details or photos please contact me
directly.

Phil Dayson