Nov. 19, 2012 at 9:44 AM ET
Dressed all in black, PSY took the stage first, sporting a version of the baggy "Hammer pants" MC Hammer made famous decades ago. Then MC Hammer himself joined in, though his outfit was all in white.
The billowy trousers didn't stop either musician from dancing up a storm, even trotting through the famed horse-riding style dance PSY tackles in the "Gangnam" video.
Hammer wasn't the only nostalgic act to take the AMA stage. Boy banders The Backstreet Boys, who celebrate their 20th anniversary next year, also made an appearance.
In contrast, the night's big winner, Canadian teen singer Justin Bieber, wasn't born until 1994, at which point the Backstreet Boys and MC Hammer were already well into their fame. Yet even Bieber himself sported a version of Hammer's baggy pants, along with a fashion twist of his own -- what appeared to be red slip-on shoes dotted with tiny black spikes. No one step on his foot!