As he has and will be called on to do at so many award shows this season, Psy closed out tonight’s American Music Awards show ceremony with his hit gone viral “Gangnam Style.” And as he has done for all performances prior, he made sure to keep things fresh with a last minute surprise After the first round of giddy up-ing, the lights went dark and we were left to consider the possibilities — Britney’s gone Gangnam, as have Madonna and The Wanted. Psy’s “special guest” could really have been anyone but what happened was probably better than anything we could have imagined, because out stepped none less than MC Hammer. Together they performed a mash-up of Hammer’s 1991 smash hit “To Legit To Quit” and “Gangnam,” and the house — and Will.I.Am in particular — just lost it. There were a lot of performances tonight, and most of them were great, but this was something else all together. It perfect surprise to call it a night.