Shouldn't Sheldon know who Radiohead are?

I was just watching the episode where they make the Penny Blossoms and at one point after Sheldon asserting that he had a working knowledge of most things, Penny asks him, "Who is Radiohead?" and he is stumped. But several episodes earlier when speaking about the one good-looking doctor who rides a motorcycle and is "in a rock band" the group confirms that they play the game Rock Band on their Xbox. The song Creep by Radiohead features in the game Rock Band and even if they had not played that song, Sheldon would have seen the title and artist while browsing the list and remembered it with his eidetic memory. Is this a plot hole?