Whats the MTV show where they would preform songs only with their mouths and no instruments?

Also there was a group that preformed quot;Baby Are You Downquot; by Jay Sean. What was their name?

it was the Singoff hosted by Nick Lachey and it was on NBC not MTV

unplugged

Unplugged

Yeah it wasn't on MTV, it was The Sing-Off on NBC. (btw its called acapella when they don't use instruments) And the group that performed Down was Nota.