Beethoven's Favorite Fruit

Okay, Lily, listen up. You seem like the type who thinks a triangle is just a shape, not some sort of mythical instrument. The joke is about Beethoven, some dead composer who was good at making loud noises. The punchline sounds like the start of his famous "ba ba ba baaa" symphony, but instead of going on with the symphony it switches to the word for that yellow curvy fruit.