Justin Vernon visited Instagram Live yesterday to preview new music for fans. During the listening session, he shared a brief snippet of an upcoming collaboration with Taylor Swift, as Stereogum points out. Listen to this below.

It’s unclear whether the song is with Swift for Bon Iver or Big Red Machine, Vernon’s project with National’s Aaron Dessner, who produced Swift’s folklore and more and more albums. Vernon worked with Swift on two songs released last year: “Exile” and “Evermore”.

As reported by the Milwaukee Journal Sentinel, Vernon also played unpublished music with the voices of Robin Pecknold and Anaïs Mitchell of Fleet Foxes. “I’m involved,” Pecknold confirmed in an Instagram comment from Pitchfork.

In a September interview with Billboard, Dessner was asked about the possibility of the pop singer appearing on a future Big Red Machine project. He replied, “I can’t really say it, so I probably won’t say yes or no. “

Swift visited Colbert last night to promote the release of their re-recorded version of Fearless.

Read Pitchfork’s cover story, “Welcome to Bon Iver, Wisconsin.”