Franz Xaver Schnyder von Wartensee (1786-1868) was a composer who wanted lessons with Beethoven.  Beethoven would only look at his compositions.

Schnyder often dined in the Mehlgrube, because he knew that Beethoven often went there at the same time in the evening. One lovely spring night Schnyder, on entering the restaurant, saw his friend Beethoven seated at one of the tables. He sat down beside him and was greeted with quite unusual friendliness and enthusiasm. “You have certainly taken a pleasant walk this afternoon, Herr van Beethoven?” Schnyder began. Beethoven: “Yes, indeed! A splendid one, a splendid one!” Schnyder: “I’ve no doubt at all, you’ve been hunting after ideas!””Yes,” Beethoven grinned. Schnyder: “If I could have the great privilege of seeing some of it . . .””Here you are, you can have the whole lot!” exclaimed Beethoven and drew a little wad of crumpled paper out of his side pocket. Schnyder pounced on it greedily and began to study it. “Well, how do you like the themes?” Beethoven asked, with a cunning and somewhat mocking glance. Schnyder: “I can’t make head or tail of it–it’s nothing but one great scrawl!” Beethoven (laughing): “Ha, ha, ha! I knew that all along, else I’d never have shown it to you.”

Hamburger, Michael (ed.) (1952) Ludwig van Beethoven. Trans. Michael Hamburger. New York: Pantheon, p. 106.