Rejex is his second release if we're looking at things chronologically, but as the name suggests this tape actually features tracks that were cut from his 1999 mixtape, and some that he recorded when he was 15 years old.
Here's what Joey Bada$$ himself has to say about this release - "Rejex is a compilation of tracks that didn't make it to my debut mixtape 1999 (obviously). I decided to put this project together because I have a lot of unreleased material that I didn't want to keep from the ears of my fans and supporters.
I also have a couple of tracks on here I did when I was 15 years old (little rachel, indubitable, and silent knight) and I want to show people the progress I've made in a couple of years. The remaining songs (flowers pt. I, catharsis, panty raid, fantum and update) are tracks I dropped prior to the release of '99 as promo only. I look at rejex as my more experimental side compared to '99. Putting together these two projects even taught me a lil sumchin about my evolution as an artist and individual."
Rejex is a great mixtape once you understand how it came to be, it's almost better to think of his two releases as one cohesive project rather than a more typical, chronological, progression. It also features incredible tunes, like Catharsis for example. Get it here, and stream below.