Taxi (1978)

Season 4, episode 20

Jim invites Elaine to a concert, and while there, they run into an important patron at Elaine's art gallery. The woman invites them both to a party, although Elaine is very worried that Jim will embarrass her in an event that's important to her career. Still, she doesn't quite have it in her to ask Jim not to go. At the party, Elaine's worst fears are realized with Jim's behavior, until he surprisingly wows the crowd on the piano and turns things around.