Just loaded GPO4 on Macbook pro 2010, running Pro Tools LE 8. I have a little experience with plug-in instruments but am in the dark on some of the fundamental concepts. Why would an instance of GPO4 allow for 16 instrument slots in it? Certainly you wouldn't load 16 instruments into a single track, or would you? Is this possible? When I have two instruments loaded in the Aria player and the Aria player is the insert in a Pro Tools instrument track, only one of the two instruments plays. If only one instrument can be used per track, it seems like in order to build a whole orchestra, dozens & dozens of tracks would be needed to be used. Maybe that's the case. Then again, I'm not sure how you would use two instruments on the same track anyway, unless they were to play the same notes. Or, maybe, with some sort of a split, where two distinct sets of notes (in differing registers) were used. Can someone please enlighten me on some of these basic principles?