In September, Bill Callahan released his new album Gold Record. Since then, Callahan and his old friend and collaborator Will Oldham have been working on a whole new project. Every few days, Callahan and Oldham, who’s working under his Bonnie “Prince” Billy alias, release another cover of someone else’s song — except in the one case where it was one of Callahan’s own Smog songs. For every one of those covers, they bring in another collaborator. Today, they’ve released their ninth. If they wanted to release a cover album, they’ve already got all the material that they might need.

After their recent covers of Billie Eilish, Steely Dan, and the late Jerry Jeff Walker, Callahan and Oldham have taken on “Sea Song,” a track from the adventurous singer-songwriter Robert Wyatt’s classic album Rock Bottom. Wyatt released Rock Bottom after suffering the accident that rendered him paraplegic. It’s a mournful, personal, experimental work.

“Sea Song” was already a pretty way-out song in its original form. Wyatt’s song is longer than six minutes, and it’s full of discordant improvisations. In their version, Callahan and Oldham have stretched “Sea Song” out even further, pushing it into bugged-out skronks with the help of Dirty Three guitarist Mick Turner. Below, listen to the Callahan/Oldham cover and the Robert Wyatt original.

Bill Callahan and Bonnie “Prince” Billy’s version of “Sea Song” is out now on Drag City, as are all the other recent Callahan/Oldham covers.