WIN! SO MUCH WIN! omg that was epic. She was smiling a lot, it's clear she was having a good time and knew how awesome that was.
There was a girl's choir - I think there were 8-10 of them? - and she started in the middle of them, she was singing while they were clapping and doing "oooh"s, then went to the piano for the second verse. Ari was there on guitar, and there was also a drummer and some other guy (I think he was playing a keyboard?)
It was so great! She sounded really good and looked SO pretty.