After reading the letter praising the Alpert roll based on a listening
to a sample file on my web site, I was going to reply but passed on it.
It is good to hear that Pauline's performance is appreciated and it
does provide further evidence that something is being done right in the
creation of these emulation files.  However this is certainly not the
way to judge a roll itself or the strengths of the various reproducing
systems.

Emulation files are best audited on a modern solenoid player.  They
are made by applying a computer model to the original roll data and
the accuracy of the performance can only be as good as the model.
I use Warren Trachtman's software to make the conversions.  Warren and
I spent some time making measurements from my pianos.  Warren based the
model on those measurements as well as my explanation of the workings
of Ampico Duo-Art and Welte.

If my pianos were perfect and if every detail of the workings of the
systems was in fact included in the model and if a solenoid player was
capable of the range of expression that the original instruments had,
then a solenoid piano could be used for comparison.  This is not the
case so we are "stuck" with having to listen to the original instruments,
fortunately.

I do believe that the emulations are quite good and are certainly good
enough for casual and even pretty critical listening however I do look
forward to a day when there is time to improve the models.

Best regards,
Spencer Chase