Hello,

I am new to this digest and do not own a player piano (unless MIDI
counts). However, I do play the piano (more than 20 years), and I am
working on a software project for my master's degree in Computer
Science and it was suggested I try posting here to see if I could get
some answers to some questions I have.  My project is converting piano
rolls to the MIDI format, and I had some questions about how the
Duo-Art expression encoding worked. I have read some literature on the
subject and searched through the archives of this digest, but do not
fully understand it yet.

Here is what I think I know with several questions:

  There is an accompaniment expression unit and a theme unit. The
  accompaniment unit controls the overall sound level of the whole
  keyboard, the theme unit makes the 'themed' notes play one degree
  (what ever that is) louder than the accompaniment. The accompaniment
  level is coded using a series of 4 perforations on the left side of
  the roll.  These perforations allow for 16 levels of expression.

        Q. Is this roughly correct?

        Q. What does 'one degree' louder mean?

        Q. Is there only one set of accompaniment control, or is the
           player divided in half with accompaniment control for both
           bass and treble?

   For theming, I understand there are 2 perforations ('snake-bites'?)
   that activate the theming unit.

        Q. Do the theming peforations affect only the notes that are
           playing at the exact same time the theming perforations are
           'playing'? Or is there some time delay between theme
           perforations and the affected notes?

        Q. Is there only one set of 'snake-bites' on the roll for the
           whole keyboard.?

I have ordered a Duo-Art roll that I can look at and analyze. If anyone
has any answers to these basic questions, I would appreciate it. And, I
look forward to becoming more knowledgeable on player pianos. When my
dad was a boy, his family owned a player piano. He is currently
collecting various rolls with the intent of buying a player for himself
some day.

Thanks for any help.

Robert

•--------------------------------------------------------------------------
Robert Pintar                           email: pintar@spk.hp.com
Hewlett-Packard Company                 phone: (509) 921 - 3605
Spokane Division                        fax  : (509) 921 - 3991