Oh and just so you know, Jessie is wearing knickers for this performance.

Earlier we showed you Miley Cyrus covering that which shouldn’t be covered, Smells Like Teen Spirit, and now the teen sensation has had the favour thrown right back at her.

Well kind of, someone much cooler has covered one of her songs, and when we say covered, this person actually wrote it, so uh yah.

Who on God’s earth are we talking about? Well only blinkin’ Jessie J!

Yup Miss J wrote Party in the USA, who would’ve thunk it eh?

Check out Jessie putting her hands up in the air and playing her song.

Well that was a bit cool, wasn't it?

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