Hi All,  While running through the internet looking for more
information on piano rolls, I stumbled on an interview with Les Paul
at http://www.beacham.com/paul/paul_radio.html.  He describes his first
multi-track recording as being done on his mother's piano rolls.

There is also interesting information of his inventions for the sound
recording industry such as "creating sound-on-sound, over-dubbing, the
electronic reverb effect and multi-track tape recording, he made the
first eight track recorder in the late 1940s by stacking eight Ampex
tape machines and synchronizing them", his involvement with Bing Crosby
and Colonel Dick Ranger and the Magnetophone tape recorder brought back
from Germany during WW2.

Some if the interview is sound clips too.  All-in-all an interesting
interview.  (Oh, he also invented the electric guitar!)

Later,
Mickey Sadler
Dublin, Ohio