Bon Iver’s Justin Vernon has teamed up with Ethan Gruska for a new song, “So Unimportant,” which is being released through Sylvan Esso’s Psychic Hotline label as part of their singles series. Gruska — who co-produced Phoebe Bridgers’ Stranger In The Alps and Punisher and is also the grandson of John Williams (yes, that John Williams) — put out his most recent solo album En Garde in 2020.