Hi Fred,

The concept of piano roll notation is simple. Perhaps the user interface for editing the piano roll notation is not so simple, but I tried to make it easy.

When you deal with piano roll notation, just imagine a real piano roll and player piano. The piano roll paper has two dimensions (actually rotated 90 degrees from what you see in Composer, but don't think too hard about that.) In one of the dimensions, the location of a punched hole determines the pitch. In the other dimension the length of the hole determines the beginning and ending of the notes.

When you deal with piano roll notation in Composer, you are metaphorically changing the position and length of the hole in the real piano roll paper.

Some Composer users might want to be able to use the mouse to drag one end or the other of the hole to the right or left. Some MIDI sequencers like Cakewalk's let you manipulate the piano roll holes (rectangles) that way. Such a mouse drag technique works for only one note at a time, however. When I designed the user interface for piano roll in Composer, I wanted to support many, many more types of editing tasks than just changing the start or end of a single note. Therefore, I settled on key strokes (such as A+RightArrow to move the attack/start of the note to the right), palette buttons, and menu items. (The menu items are not intended for regular use, but only as a way to learn the key shortcuts, which you can learn just as easily by hovering the mouse over the palette buttons.) Since the mouse drag operation would work only for changing a single note, and since the mouse drag operation would conflict with other interpretations of mouse drags in Composer, I decided to leave that option out of Composer.

Cheers
-- Mark