The kid still has his fans, and he’s by no means a lost cause, but one of my great rap disappointments this year has been the young Brooklyn rapper Joey Bada$$. Joey’s 2012 breakout mixtape 1999 was a ’90s-revivalist affair for sure, but it had a giddy energy working for it. Joey and his friends had this fresh-faced sense of discovery about them, like they were trying their hand at this music just as they were discovering it, and like they were super-amped to discover that they were good at it. But that revivalist aesthetic can’t be a dead end; it has to go somewhere. 1999 had possibility to spare, and it was exciting to think what Joey would do with his gifts. Thus far, though, he’s done nothing with them. On this year’s Summer Knights mixtape — and, even worse, on halfassed one-off tracks like this — he’s stayed rooted to the same boom-bap style, doing it with less energy and more hoarse boredom, sounding progressively less motivated every time I hear a new track from him. Joey has a lot of tools, but he’s not a great rapper yet, and he needs to push himself to get there. He doesn’t seem too interested in doing that. Compare that to the young Brooklyn duo the Underachievers, Joey’s colleagues in the loose Beast Coast movement, and you start to see what routes Joey might take if he wanted to avoid a prolonged rut.

The Underachievers came up earlier this year with Indigoism, a really good mixtape that brought back a certain near-forgotten loopy, antic strain of late-’90s backpack-rap. It was a fun stoner record, one that messily sprawled up with its sneakers on your coffee table, demanding snacks. Issa Dash and Ak, the two rappers in the group, sounded like they were still finding their voices but having fun doing it, rapping about blunts and pyramids over dazed horn loops and organ-fart circus music, never particularly interested in being the coolest guys in the room. That friends-bullshitting style is sort of a delicate one, and it won’t necessarily translate to too many contexts. When I saw the Underachievers at SXSW, they blended into the grimly competent lineup of New York rappers whose bill they were sharing, and there was never much evidence that they’d have more in the tank after that tape. But on The Lords Of Flatbush, the duo’s new mixtape (named after a low-budget street-tough movie that Sylvester Stallone made before Rocky), they’ve pushed themselves, and they’ve found a way to keep themselves from falling into any sort of rut.

Here’s how they did it: They found the producer whose style was as far from Indigoism as they could possibly get, and they got him to produce almost all of the new tape. That producer is Lex Luger, from Virginia, a master of epic crush-your-face bangers. Luger is probably about the same age as both Underachievers, but he had his big spotlight moment a couple of years ago, when he was responsible for murder-death-kill anthems like Rick Ross’s “B.M.F. (Blowin’ Money Fast)” and almost all of Waka Flocka Flame’s enormously important hour-long assault Flockaveli. For a little while there, everyone was trying to hire Luger or, failing that, to find people who could make beats just like him. Kanye West threw actual opera singers over Luger’s already-operatic churn on his and Jay-Z’s “H.A.M.” It was a whole thing. The sound of radio-rap has changed since then, drifting toward an urbane emo synth-float thing. And Luger has since altered his style, too, easing up on the orchestras of raging ghouls and developing an eerie keyboard-stomp. That new style is the one you hear on The Lords Of Flatbush. And even if it’s nowhere near as face-damaging as his work on Flockaveli or Juicy J’s Rubba Band Business 2, it’s still miles harder than anything the Underachievers were doing on Indigoism.

On The Lords Of Flatbush, Luger and the Underachievers find a middle way, with the two rappers flexing fundamental virtuosity over dark, strobing club beats. The combination works weirdly well. The two rappers are still working on developing their personalities, and I still can’t tell them apart aside from their different vocal octaves. Both guys rap about weed and about being good rappers, and neither one says much that I feel like I need to transcribe and quote back to you. But they’re slick, nimble presences, and it’s fun to hear them sprinting and weaving all over these beats. And even if they aren’t “Hard In Da Paint,” these beats are hard — monolithic things with titanic drums and eerie Casio melodies. At the end of the tape, the Underachievers go back to their old sound, the emotive guitar-moan samples and the gasping organs. That stuff still sounds great, and they sound more comfortable rapping on it than they do on the Luger beats. But over those Luger beats, you can hear them trying new things: Rat-tat-tat double-time flows, tougher intonations, violent grunts. And even if the end result isn’t as immediate and rewarding as Indigoism (and even if it’s about half the length of that one), it’s a clear sign that these guys are willing to explore different musical ideas and expanding their skill-set. I don’t know if they’ll ever put it all together and make an absolute classic, but I do know that they’re closer to it now than they were before this tape.

Download The Lords Of Flatbush here.