Ke$ha 'most proud' of Britney Spears song

Ke$ha has revealed her motivation for giving away the song 'Till the World Ends' to Britney Spears.

The 'We R Who We R' singer spoke to New York Magazine about giving the song to Spears, stating that the move helped solidify her as a songwriter.

"I've never been more proud of anything in my career," Ke$ha said. "It really solidifies me as a songwriter in the pop music world, which is what I consider myself first and foremost. So it actually is really, really exciting for me when I hear [Britney] sing it."

Ke$ha continued: "When I hear my own songs on the radio I have to kind of turn it down or change the radio or whatever. When I hear ['Till the World Ends'], I f**king blow the speakers out and I order everybody to dance."

Hangover Part II star Zach Galifianakis recently declared that he is not a fan of Ke$ha's music, claiming that it promotes a bad message.

A new song from Ke$ha leaked online last week. Titled 'Tease Me', it is not yet known if the song belongs to the singer's upcoming album or if it is a reject from her previous one.

Listen to Ke$ha's 'Tease Me' below: