Keith Urban shares the story behind his recent collaboration with Taylor Swift

In a new interview with Ellen DeGeneres, the country star shared the "craziest" story behind his recent collaborations with Taylor Swift. "We were in I'm at the shopping mall, doing my Christmas shopping, and I get a text from Taylor saying, ‘I've got these couple of songs I want you to sing on, do you want to hear them?'" Keith recalled on The Ellen DeGeneres Show. "I said, Sure. So she sends me the songs, I'm sitting in the food court, listening to these two unreleased Taylor Swift songs," he continued. "I loved the songs and luckily got to put a vocal on both of those." As fans of the artists may know, Keith's vocals are on two tracks of Taylor's newly released album: That's When and We Were Happy. The two songs are part of Taylor's Fearless (Taylor's Version) album, which dropped on April 9. Taylor re-recorded the 2008 Grammy-Award winning record after a dispute with her former label, Big Machine, over the master rights to her songs.