He's a bit like that Tiger bloke, who was on 'Later...' a few weeks back. In fact, as Cullem was describing how Hauschka fiddles about with the innards of the piano I thought it was the same guy, cos he had the lid up and twanged a couple of strings during his piece. Still, the track was played and it sounded fantastic.
The late (and very lamented in my pod at least) Esbjorn Svensson of the magical EST used to do stuff like that and the drummer and double-bassist also used to occasionally add electronic jiggery pokery to their things. Great stuff.