I'm glad our little recording project has created some interest!
Let me respond to some of the points raised.  Bear in mind that I'm
no expert in tuning or musicology so please correct me if necessary.

- Although recordings of the two temperaments do exist, I know of
none that are both a) otherwise identical and b) played on a real
instrument.  Identical, because an a/b illustration should differ
only in the temperament.  Real, because I suspect that the resonances
of a real instrument matter, and it's unclear to me that digital
pianos designed for equal temperament are capable of reproducing the
resonances of another.

In short, the reproducing piano helps us to be not more authentic but
more scientific.  Also I just prefer real instruments and it's fun to
put a reproducing piano to use in this way for a friend!

- Thanks for the links to criticism of Lehman's ideas.  I should add
that we don't advocate the one temperament or the other.

- Interesting that the difference is clearer on a harpsichord.  Would
there were automatic variants of these we could try this on!

 [ MIDI-controlled harpsichords do exist; ask about them!  -- Robbie

- Unfortunately Ampico covered only four of the 48 pieces that comprise
the "Well-Tempered Clavier".  If it were possible, yes, it would be
great to do this for them all.

We're simply curious to compare as best we can how the temperaments
sound.  This motivates our choice of Bach: we want to show each
temperament in its best light, and Bach, if Lehman is right, composed
the WTC for that particular temperament.  Nor is this unfair to equal
temperament, as it renders everything equally well (or equally badly
depending on one's viewpoint!).  So the Ampico roll, despite containing
only four pieces from the complete work, should furnish an adequate a/b
illustration of the two temperaments.

- Thanks for the interesting background on Bach's practice.

Lastly, someone has kindly offered to lend us their roll 65233G.  Thank
you!  Although the timeline is tight it should arrive by our recording
date of 23rd April.  I will post here a link to the recording when it's
available.

Best wishes,
Richard Procter