Callie auditions for the play to make Jesse feel less shy about doing it. She's a horrible singer and the director cuts her off early. Even so, she succeeds in making Jesse laugh.
After a Failure Montage of the cannon not working, Callie finally gets it to work during the cafeteria preview of the play. She understandably cheers.
Jesse keeps saying while he likes singing, he hates going onstage. What happens when Bonnie refuses to come out for Act Two on the last night? He puts on the dress and takes her place, without missing a beat. The kid earned that standing ovation.
On the other end of the scale, it's strangely cathartic to watch Bonnie get a sound scolding from the stage crew and the staff after she let her feelings get in the way of finishing the show. After seeing her act like an absolute snob and look down on everyone else, she's rightly humbled.
After Jesse essentially "cheats" on her with West, Greg approaches Callie and tries to start a relationship with her right then and there. A lesser person would've taken it as a compensation, given Callie had a crush on Greg. Instead, she recognizes he's only going out with her because Bonnie won't go out with him anymore, and turns him down. After going through so much drama, she realizes she wants something more.
