I know this because when I'm playing piano, I can't talk or I make mistakes ^^

That's not the official definition of "one man band", it really means playing one instrument at a time. So you have to play it a total of 4 times (one on each instrument). However the phrase for singing and drums at the same time is "voxdrum" and for guitar is "voxtar" and you get the idea.

Stop bumping threads.

now that its bumped...i guess ill give this a go when i get my 360 fixed.