I believe it was at the St. Louis AMICA convention that Ramsi Tick gave
a wonderful presentation on the history of the QRS piano roll company.

The two theories behind Q.R.S. that I recall, since the Melville Clark
company that produced the rolls was into many other consumer markets,
were:

1. As the piano roll segment of the company grew, the roll orders in
the "R" bin flowed into the "Q" and "S" bins.  Hence the piano rolls
were named QRS.

2. Q  Quality
   R  Real
   S  Service

Don Barton - Barton Player Piano Co.
Minneapolis, Minnesota