Ke$ha "freaked out" when The Strokes agreed to work with her.
The 'Tik Tok' hitmaker asked the group's frontman Julian Casablancas and drummer Fabrizio Moretti to perform on 'Only Wanna Dance With You' from her new album 'Warrior' and loves the fact she is making music with musicians most people wouldn't associate with her style of music.
She said: "They just were down [for it], and I was down.
"A friend of mine plays with Julian and we kind of knew each other, and Julian really likes [producer] Dr. Luke so they were talking, and it kind of happened, oddly, organically, and in a strange way.
"I'm a huge fan of their music, and they're on one of my favourite songs on the record. They're part of a long list of some of my favorite bands that have actually collaborated with me on this record. It's really exciting for me to work with people that are unexpected. I hope people freak out. I kind of freaked out when he was like, 'Sure.' I was like, 'Really?!' "
The album also features a track with Patrick Carney from The Black Keys and Ke$ha likes the fact their collaboration stemmed from a close friendship.
She told Spin magazine: "Patrick's actually a really good friend of mine. I just went to his wedding a couple of weeks ago. I really wanted to capture that essence that my mum used to talk about - all my favourite records were made of people being friends and jamming and making music in an organic, spontaneous way, and I wanted to capture as much of that in a pop record as I could."
'Warrior' - which also features a collaboration with Iggy Pop - is released on December 3.