Archive photo of Prince by Herb Ritts

Tuesday's arrival of Prince's posthumous greatest hits album 4Ever also includes a previously unreleased track "Moonbeam Levels."

The slow-burning cut was recorded in 1982 and is said to have been intended for the late singer's album 1999. Prince is believed to have worked on the song again in 1989 before ultimately abandoning it.

While Prince himself never released it, Elvis Costello tapped into the vault and covered the track in 2013 during a fundraising tribute to Prince at Carnegie Hall.

The two-disc, 40-song 4Ever is otherwise not much unlike past Prince compilations, minus the release of "Moonbeam Levels" and a 12-page booklet of previously unreleased Herb Ritts photos of the Purple One, such as the one seen above.

4Ever precedes next year's expected reissue of Purple Rain, which label Warner Bros. Records has suggested might be accompanied by a second disc of unreleased material and bonus tracks.

ABC News played "Moonbeam Levels" during a listening party at New York City’s Cutting Room Studios. The stream can be heard in the video below.