Bon Iver, Alicia Keys to Collaborate

Bon Iver Announces U.S. Spring Tour

Bon Iver's Justin Vernon might be indie rock's busiest performer. The Grammy-nominated musician, whose past collaborations range from Kanye West to the National to Kathleen Edwards (whom he joined for a World Cafe performance this week), is about to add another: Alicia Keys.

The musician told USA Today that he's written songs with the R&B singer, and would like to feature her on an even larger project.

"I have a big idea to do an American songbook of the greatest women singers. There are so many: Casey [Dienel] from White Hinterland, Bonnie Raitt, Alicia," he said.

Vernon will also make a guest appearance on the Chieftains' upcoming album and recorded with the Flaming Lips for the band's own collaborative album, which is slated for an April 21 release.

He's squeezing in time for his own band, with Bon Iver set to perform on this weekend's "Saturday Night Live" and the band up for several Grammys, including Record and Song of the Year, at the Feb. 12 ceremony.

As for a follow-up to the critically acclaimed "Bon Iver," Vernon said it could take years.

"I don't have songs written yet," he said. "I'm guessing three years. But it could be five. It could be only one more. It just depends when the songs come about. I sort of have to wait till they reveal themselves."