Gilbert Chang wrote:

>BTW, can anyone explain to me how a reproducing piano works? These machines
>allowed us to hear Saint-Saens, Ravel, Prokofiev, etc., play their own
>works, but I have no idea what they are.  Thanks.

I have CD-1 of Recorded Tresures which features piano rolls of Busoni
playing Liszt, and there is a good description of the Welte system invented
in 1904.

Briefly, a roll of lined paper was on a spindle.  Poised over each of the
100 lines on the paper was a little wheel of extremely soft rubber with
pointed edges.  Each wheel was in contact with an ink supply.  Under the
keyboard was a trough filled with murcury.  Attached to each key was a slim
rod of carbon.  As the key was depressed, the rod dipped into the mercury
and an electrical contact was established between it and an electro-magnet
connected to the corresponding inked rolls in the recording machine.  The
harder the pianinst hit the key of the piano, the faster the carbon rod
would plunge into the mercury and the stronger the corrent between the rod
and the electro-magnet would be.

The harder the inked rubber wheel was pressed against the moving paper
roll, the wider the mark printed on the paper.  The pianist's pedaling and
speed of attack was captured in the same way.  After all this, there was a
conversion of the ink to an electro-conductive material which could be read
by the "vorsetzer" which actually played the piano based on the information
on the roll of paper.

The Vorsetzer ("Something set above or before" in German) was rolled up
to the piano, and little "fingers" depressed the keys of the piano.  If
the artist approved what he heard himself play, rolls of paper were hand
punched following the inked patterns and sold to the public.

This is probably more than anyone wanted to know, but here it is.  It seems
a bit odd to me that this system was at all practical.  Several sources say
that there are VERY few Votsetzers in existance today, so how many could
have actually been in homes?

I have not heard anything about this CD company, but they evidently
intended to produce more Welte CD's.  The Busoni'Liszt is interesting, but
suspect because of the strange fluctuations in tempos.  There seems to be
no mention of how the speed of the roll was determined.

Joel Hill
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Tallahassee, FL