Kesha brought her signature brand of party pop to the 2013 iHeartRadio Music Festival -- and some special guests, too. The 'Crazy Kids' singer was joined onstage by none other than rock legend Joan Jett ... and by Kesha's own best friend, Jack Daniels.

K-Dollar Sign opened her set with a rousing rendition of 'Die Young,' wearing a black leather body suit and sporting sparkling, smoky eyes and a whole lot of body glitter. Her choreography was on point and she commanded the stage with her dancers, who sported their usual cult-like skull makeup for the track.

Before launching into 'We R Who We R,' Kesha made the Las Vegas crowd promise to "be themselves, unapologetically, always, 'cause we are who are!" The performance was what you'd expect from the whiskey-soaked goddess, save for the end, when she ditched the dancing for an electric guitar.

Next up was 'Blow,' complete with a grinding breakdown, followed by 'Dirty Love' from 'Warrior.'

She followed with a special guest, someone who loves rock n' roll as much as she does -- Joan Jett! The rockers did a duet of 'Bad Reputation,' one of Jett's signature songs, and Kesha took a swig of Jack straight from the bottle while Jett did her solo.

The Cannibal Queen closed her set with 'Tik Tok' -- of course -- and made fans wish time would stop so they could watch her wail and writhe forever.

Christopher Polk, Getty Images
Christopher Polk, Getty Images
Christopher Polk, Getty Images
Christopher Polk, Getty Images
Christopher Polk, Getty Images
Christopher Polk, Getty Images
Christopher Polk, Getty Images