Okay, lemme get this straight:  The average person who thinks about it
at all assumes that piano rolls were made with a special piano that
had pencils on each key.  The artist would sit at the piano, start the
paper rolling, play the tune, and when he was done, there'd be a paper
roll with pencil marks on it.  Then someone would punch holes where the
pencil marks were, and that would be the master roll; from it would be
punched the duplicates.

 [ Lots of editing was applied after the marked lines were punched.
 [ This method (the marking piano) produced "Hand-Played" rolls.
 [ Expression codes also could be added by hand.  -- Robbie

Then I read that they'd put the roll through the marking piano a couple
of more times in sort of a sound-on-sound technique, where the artist
would listen to what he'd already recorded and add extra parts to it.
The resulting extra pencil marks would be punched out, thus producing
a roll that looked like it was produced by someone with nineteen
fingers.

 [ The computer controlled recording piano and perforator at Play-Rite
 [ Music Rolls was occasionally employed in this manner, and I used
 [ the setup in 1982 to make a few rolls of Hank Williams songs.
 [ After I finished editing all the errors of overlapping notes that
 [ four hands can create I wished I'd used the 'drafting board' method
 [ instead!  -- Robbie

And I also read that the artists didn't need a piano to add the extra
embellishments.  And now I seem to be reading that they didn't even
need a piano to produce a roll at all; that they could record it with
a hand punch on a table, because they knew what it would sound like
just by looking at the punch marks.

 [ Yep, just like Beethoven after he became deaf.  -- Robbie

If I've got this right, it's thoroughly amazing to me, though I am
equally amazed when someone can sit and listen to music in their head
just by reading the notes off of sheet music.  Is it correct?

 [ You do the same mental process when you read a printed message from
 [ a friend and you hear the writer's voice in your head!  ;-)  -- Robbie

Mark Kinsler
Lancaster, Ohio USA
http://www.mkinsler.com/
http://howthingsoughtawork.blogspot.com/