Howdy Erwin,

Trust me - there are no dumb questions! GPO is a wonderful library, and there are so many variables that you can use to get so many nuances out of the instruments, that it can be a bit boggling!

With GPO, the "attack" of the notes is dependent on the Mod wheel. You can still use the volume control to control the volume of that attack, but you must have some sort of mod wheel value that's high enough to get GPO to give you sound.

So, you can do things a couple of ways. If you're just messing about with GPO, you can use either the mod wheel on your MIDI keyboard to work with volume, or you can use the mod wheel on the virtual keyboard for GPO.

When using Composer, if you're recording into the program and want to use the mod wheel for volume and dynamics, Composer will record these as you perform on your MIDI keyboard. Or, if you want to edit the Mod wheel graph after you enter your notes, you can do it that way, too. This allows you to either set a constant value, or to use the Mod wheel graph to get some very convincing dynamics out of the instrument performances.

I hope this is helpful!
Sherry