Every few years, rock aficionados are treated to another collection of unreleased Jimi Hendrix studio recordings. The incomparable guitarist has put out 13 studio compilations since his untimely death, which is ten more than the three albums he released with the Jimi Hendrix Experience during his lifetime. The latest addition to his posthumous catalog—and the third volume in a trilogy of releases that includes 2010’s Valleys of Neptune and 2013’s People, Hell and Angels—is a forthcoming compilation titled Both Sides Of The Sky, and it’s out today via Legacy Recordings.

The new “album” was compiled from a number of studio outtakes recorded while Hendrix was working on a follow-up to Electric Ladyland between January 1968 and February 1970. Hendrix’s Band of Gypsies collaborators Buddy Miles (drums) and Billy Cox (bass) join him for most of the tracks, though his Experience bandmates Mitch Mitchell (drums) and Noel Redding (bass) can be heard on one of the tunes.

However, one of the most interesting things about Both Sides Of The Sky is the inclusion of a few of Hendrix’s collaborations with other rock legends. The release features appearances by Stephen Stills—who joins Hendrix for his own “$20 Fine” as well as a rendition of Joni Mitchell‘s “Woodstock”—and another effort with Johnny Winter, who contributes his chops to a cover of Guitar Slim’s “Things I Used To Do”. Saxophonist Lonnie Youngblood also helps out with a lengthy take on the Hendrix rarity “Georgia Blues”.

Producer and engineer Eddie Kramer, who mixed and recorded every album Hendrix made before his death in 1970, and co-produced Both Sides Of The Sky, recalls the studio experience with Jimi in a new interview on NPR:

“He did have a tendency to describe sounds in colors… If he said, ‘Hey, man, give me some of that green,’ I knew exactly what he meant; it was reverb. Or if he said, ‘Hey, man, more red,’ I knew it was distortion. And then if it went purple, it was really stupid distortion.”

“He used the studio as a rehearsal place, and thank goodness that was happening, because tape was running and he would bring in different musicians to try to figure out what he was going to do with his musical direction.”

It would sometimes take Hendrix up to nine months to complete a song, according to Kramer. He also confirms that there’s a lot of unreleased studio recordings left in the vault, and is just as excited to share the timeless material. “I get so excited,” he says. “I want to keep doing Jimi Hendrix for the rest of time.”

You can read the full story on NPR.