BTW, there is a good and consistent fix to the alarm-interrupting-the-Mahler-symphony problem. When the user chooses to mute the iPhone and there's an alarm that's going to ring in the next three hours (a reasonable upperbound on the length of a performance, a concert, play or movie) warn the user that the alarm is going to ring even though the phone is silenced.  

It's like advising the user that saving something will overwrite an existing file. It's just good manners to let the user know about possible negative consequences of their actions.