My only concern here is "What if the band playing wants to be recorded?" I'm not talking about some big-name group playing with all their flashy lights and huge packed stadiums of people, but if this technology works by, say, recognizing that there is a drum, two guitars, and a microphone in the view of what's being recorded, what's to stop this tech from preventing you from filming, say, a high school band who would like to encourage their few fans to tape the sessions so their image can spread.
I'm not saying it would be very important in the long run but Apple would have to be extremely careful in implementing this tech to make sure it only blocks what it's supposed to block, and nothing more, or else they're going to have a lot of complaints about legitimate videos being cut off because the phone thinks they're trying to pirate.
Also, Apple has to realize that they're not alone in the smartphone market. Patenting a technology like this actively prevents their competitors from using it, meaning people who want to be able to record performances with their smartphone may decide to pick up an Android or other competitor instead of sticking to their iPhone.