Chris SmithX

I have footage from two cameras of a school music performance. One camera has all the footage, and the other is from a cell phone, showing just a clip from a different angle. I want to add the cell phone footage to the main footage with a crossfade and then cut back to the main camera footage again. So the key point is getting the footage synchronised. It's classical music with violin bowing, and some repetitive bits. The cell phone clip runs for about one minute, and the full footage runs for 3 minutes, so I need to place the cell clip at the right point in the main footage, so that what you see after the crossfade (to the cell phone clip) and what you hear (main footage audio) match up. How do I do this?