For the last two years, Kendrick Lamar has been breaking all the rules by popping up on late-night shows and awards shows to perform new, never-heard-before songs, without warning or explanation. After he lit the stage on fire at the Grammys while performing a still-untitled new song, he finally provided a little more background: “I got a chamber of material from [To Pimp a Butterfly] that I was in love with where sample clearances or something as simple as a deadline kept it off the album,” he told 2 Dope Boyz, describing “probably close to ten songs that I’m in love with that I’ll still play and still perform that didn’t make the cut.”

Now, Lamar has opened up that chamber and released Untitled Unmastered, a new, eight-track album sporting an all-black cover. The title might lead you to think that the new LP is more tossed-off than it actually is: These tracks are every bit as jazzy, orchestrated, odd, and full of virtuosic rapping as the ones on To Pimp a Butterfly. It also plays more like a cohesive album than you might expect, complete with a track that serves as an intro and recurring motifs (for example, the cries of “Pimp, pimp, hooray!” that repeat across multiple tracks).

And while it’s true that many of the songs are years old (the song performed on The Colbert Report in December 2014 appears as “untitled 03 05.28.2013,” and the song he performed on the Tonight Show in January appears as “untitled 08 09.06.2014”), Kendrick and co. seem to have continued working on the songs as recently as this year, when Swizz Beatz’s 5-year-old son helped produce “untitled 07 2014 – 2016.”

You can purchase the album on iTunes, or stream it on Apple Music, Tidal, or Spotify.