An explanation from the horse's mouth on the origin of "Q.R.S." can
be found in this video --

  http://www.youtube.com/watch?v=i3FTaGwfXPM 
  Piano roll production at QRS Music
  A late-1980s tour of QRS Music's piano roll manufacturing facility
  in Buffalo, New York, originally aired on the TVOntario children's
  show "The Acme School of Stuff".

Regards,
Jack Scarsbrook

 [ At time 6:58 the narrator says, "Company legend states ..."!  ;-)
 [ -- Robbie