Watch Elvis Costello Lead a 'New Basement Tapes' Jam

Jim James, Marcus Mumford and more back the singer on Bob Dylan's unreleased "Six Months in Kansas City (Liberty Street)"

Twenty-fourteen, it seems, is the year of the Basement Tapes. Recorded in 1967 and first reported in a 1968 Rolling Stone cover story, the legendary collaborations between Bob Dylan and the Band were partially released in 1975 and have been bootlegged for nearly 50 years.

Now, the full 138-track collection is coming out on November 4th. One week later, Lost on the River: The New Basement Tapes, follows close behind, featuring a supergroup of musicians tackling lost Dylan lyrics; and on November 21st at 9 p.m., Showtime is exploring the new tapes' project with a documentary titled Lost Songs: The Basement Tapes Continued.

Watch Elvis Costello, Marcus Mumford, Jim James and the rest of this new (lowercase) band take on "Six Months in Kansas City (Liberty Street)," one of the final tracks to appear on the album, right here. With a trio including Carolina Chocolate Drops singer Rhiannon Giddens nailing the back-up vocals and almost outshining the rest of the unit, Costello and company roll through the track, building to stunning close that finds them repeating the title again and again. T Bone Burnett sits behind the mixing board, nodding and smiling.

"T Bone called me and told me that he had these unpublished Dylan lyrics from the time of the Basement Tapes," Costello says elsewhere in the documentary, explaining the genesis of the project. "I said, 'Well what are they like?'" Later, Lost Songs features an original interview with Dylan himself, in which the songwriter helps provide an answer to that question.