How much you plan your shots depends on how casual or important the event is. If it’s an elementary school play, you can probably be low key in your approach. If it’s a very special occasion, such as your music major daughter’s college piano recital or a wedding, you need to plan your shoot in more detail.
The pressure in a live event is that, as they say in show business, the show must go on. Events force you—like the performers—to be on your toes.