Buttah smoove R&B crooner Usher got his groove on with the Afghan Whigs at SXSW this year. We don't normally associate Usher Raymond with rock music, but he threw us for a loop. It was an unlikely pairing, but somehow, it worked on the cosmic level. SXSW is all about the music, and this collabo was proof positive.

It was Usher's first-ever SXSW appearance, and he made it memorable.

The Whigs' full set at the Fader Fort is above, but you can scroll to the 16-minute mark to enjoy their special guest. They were covering Usher's 'Climax' so it was only right that he would come out and join them to get the job done.

After Usher helped the Whigs finish his song, he stuck around to perform their track 'Somethin' Hot.' One good musical turn deserves another.

Gliding on the stage, wearing a fedora and a leopard print, military-style vest, Usher brought a clinic of smoothness to the rock show.

"What's up, surprise, surprise, Austin, make some d--- noise!" Usher said, taking over the show. He called the Whigs "indie rock royalty" and himself fortunate to be able to groove with them.

His encore consisted of 'Bad Girl' and "U Got It Bad,' which you can watch below.

Watch Usher Perform 'Bad Girl' + 'U Got It Bad' at the 2013 SXSW Festival