This is a mixtape of demos, remixes and unreleased tracks dating from Sufjan Stevens’s magnificent 2015 album, Carrie and Lowell. The catnip for Stevens completists here consists of four previously unreleased outtakes – including Wallowa Lake Monster, a riveting song that weaves myth (monsters, feathered snakes, Charybdis), memories of his mother, and Stevens’s feather-light electronic backings. The other unreleased gem on The Greatest Gift is City of Roses, a sweet-sounding track full of dread. Nothing here feels like filler, however; not least two versions of Drawn to the Blood, one electronic and one fingerpicked.