Kesha Rocks Out With Joan Jett + Jack Daniels at 2013 iHeartRadio Music Festival [VIDEO, PHOTOS]

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.