i haven't taken DS to a musical as such - just play school concerts & the dorothy the dinosaur show twice. he also loves music & dancing. all this is since he turned 2 (i think) and he's been okay & seemed to enjoy them but they have been no longer than an hour. tbh, he has needed space to move & i don't think i could have contained his energy much past the hour. i think much of it depends on the individual child (and also whether the show is geared to children or adults) but until DS has more of a concept of time & understands better why he needs to sit still/in his chair, then i wouldn't take him to anything longer (he's almost 31 months). i should clarify though that he definitely has a serious case of ants in his pants & rarely stays still unless he's asleep.