After his first-ever appearance at the Grammys, the Twitterverse is wondering: Just how old is Mick Jagger, anyway? The Rolling Stones' front man performed a tribute to soul legend
, who passed away last year. Jagger wasn't the only music legend to perform. Bob Dylan and Barbara Streisand both took the stage, while Christina Aguilera almost fell off it. Other highlights included Eminem dropping an F-bomb while performing with Rihanna and Lady Gaga hatching from a giant egg to perform her new
. Arcade Fire took home top honors for their album
. As for Mick Jagger's age? He's a spry 67 years old.