Funny stuff. I thought the Gould imitation was spot on. I don't listen to Lang Lang enough to hear how accurately you imitate his style but still it was quite amusing. As to Argerich, I'd say you captured something of her tempestuousness and with regard to Pollini, I'm afraid that the only recordings I have of him don't feature his singing, so I'll have to take your word for that little bit "extra."
Anyway, top marks for some inspired clowning, which requires both perception and good fingers.