It's not enough to hit the notes. There is no point in the singers just standing there and sounding wonderful if they're not connecting with the characters they are portraying.
Nursery schools and bars at 2 a. m. are the only places where it is completely normal if someone just spontaneously throws up on the floor. . . and just like a toddler, the bar patron wakes up the next day not remembering or caring how they behaved.