In response to Leonardo Forti, I have a 1909 Hupfeld Phonoliszt
Expression Piano which is fully operational and I can assist him
with any questions if he wishes to contact me directly as I have
worked on the piano and understand its functionality.  The Phonoliszt
system was a very early all-electric design that does a very good job
of 're-performing' the original live performances of concert pianists
of the time.

I have a large library of original rolls, some of which are arranged
rolls but many are labelled 'Concert' and are live performances of
noted pianists of the day.  All rolls are watermarked and dated on the
back of the leader.  Hand played rolls include a small photo of the
pianist and a signature.  The Hupfeld masters were later used for their
fully reproducing systems and I believe some were sold to Ampico in
America.

The scale is based on the early Hupfeld 73-note roll of 11-5/8" width
and has five expression ports across the centre, alternating with
playing notes.  These five ports are used for different functions on
the Phonoliszt, Clavitist and Helios scales so it is important to use
the correct roll on any particular piano.  Some rolls also use the low
and high note perforations for additional functions such as bells or
mandolin control.

Best regards from the UK,
Nicholas Simons