The Bon Iver star said that he has recorded vocals on "at least ten songs" with the rapper.
Vernon told Pitchfork: "That whole first week I was there we worked on the 'Woods' song, which is called 'Lost In The World'.
"We were just eating breakfast and listening to the song on the speakers and he's like, 'F**k, this is going to be the festival closer', I was like, 'Yeah, cool'. It kind of freaked me out."
He added: "It was the same kind of thing, throwing ideas around. There are a bunch of other songs I'd just throw down on, write a little hook, whatever. In the studio, he was referencing Trent Reznor, Al Green, The Roots, the f**king awesomest s**t. It made total sense to me."