He deals with abuse well.
I had to read the Wikipedia article to contextualize this scene and this movie sounds like hell to sit through. Guess that's how things get nominated for Oscars. Weird Al tries to improve on his flawless accordion tootling under the direction of J.K. Simmons. He is beaten, but his spirit is not broken, even when he gets hit by a chair.
"Why do you think I just threw that chair at you?" asks J.K.
Al answers, "You're trying to win an Oscar?"