Brian - You probably have already thought of this but I'll mention it just to make sure that it is considered while you are writing the software. Six instruments get a bit small on a seven inch screen making them hard to read. I've seen other programs where if one instrument is taped, the other five instruments disapear and the taped one fills the screen. One more tap brings the six-pack back to the screen.
Another thought - Maybe it would be better to be able to zoom in to one instrument and then pan around to see the others.
Jim Williams