[Eyes still closed, he rests his hands on the keys for a moment, then starts to play. He slows it down quite a bit while he's learning, but there are a few slips where he hits the wrong key and has to start again. It's still quite impressive for a first try, though.
Tamaki also might notice that Kaworu doesn't use the pedals at all - his intuitive knowledge of piano playing doesn't extend that far- which gives his playing a bit of a hard edge.]