Mickey Sadler suggested Harmony Assistant as an interesting program
to make organ books.  I took a look at this program and it is great.
Simple to work with, a user friendly interface and of course the
possibility to make organ books and rolls for any kind of organ.  It
lacks one feature: the possibility to edit your music in a piano roll
window.

When you make an arrangement, you listen to it and make a lot of little
changes, such as shortening notes or groups of notes, add ornamentation,
let bass notes start a little earlier than other notes because of their
slower response, and so on.  All these changes are much easier to do
when you work in a piano roll screen.  You just select the blocks that
represent the notes, move them, make them smaller, add some other ones
with a click and so on.

I really hope they decide to add this feature to their program at
Harmony Central.  This would be a major bonus.  Hope they read this
message.

Jacques Thijs