In late March, Keith Urban shared the track listing for his upcoming new albumRipCORD, but he apparently left out one very important detail: One of the project's 12 tracks features Carrie Underwood.

Urban first let the news slip to ET at the 2016 ACM Awards, saying, "I got Pitbull, and Carrie's on the record -- Carrie Underwood's on there, as well."

Following the first half of American Idol's series finale on Wednesday (April 6), Urban added, "I wrote this song with this guy called busbee. The song is called "[The] Fighter." I would say it's a call-and-response song between a guy and a girl, and Carrie's on that song with me."

According to the RipCORD track listing, "The Fighter" is the record's eighth track. It was both written and co-produced by busbee and Urban.

The country superstar had previously shared that rapper Pitbull contributes a verse to a song called "Sun Don't Let Me Down," which also features Nile Rogers; Rogers plays guitar on that track, while Urban plays the banjo.

RipCORD is set for release on May 6. Urban recently released the disc's third single, “Wasted Time.” The tune is uptempo and features an electronic beat throughout, along with hints of banjo; it is poppy, but it retains a touch of country. Urban, Greg Wells and J. Hart wrote “Wasted Time,” and Urban and Wells co-produced the track.

See Keith Urban + More Country Stars Then and Now

Unforgettable Keith Urban Moments

More From TheBoot