Bizzarely, there's also a story where Doom is about to destroy the Fantastic Four with a mind disintegrating piano *presumably while playing an insanely difficult piece, because, hey, he's Doom* when he notices one of his Nazi employees chasing a spy through his art galleries with a flamethrower.
He uses the piano to kill the Nazi and save his art, and then lets the Fantastic Four go because he's no longer in the mood.