Opening a "Part" should solo that part, rather than mute all other parts.

Hope this is clear. I can see an argument for unmuting the other parts one by one to hear the part you're looking at in context with specific instruments, but it would be my preference to do that by soloing more parts rather than unmuting them.

My main issue with the way that it is now is that you can't hear the part your looking at in context with the rest of the instruments in one click, as would be the case if that part were opened solo'd, rather than with all the other parts muted.

Also the mute button on the master fader still doesn't work.