When it comes to pairings we never thought we'd see, Taylor Swift and Mick Jagger rank somewhere near the top of the list.
But last night in Chicago, it happened. During the Rolling Stones concert at the United Center, the band was barely a few bars into "As Tears Go By" when Swift appeared alongside Jagger to lend her voice. It probably took some fans by surprise, but it wasn't exactly a secret seeing as Jagger tweeted about it earlier in the day:
