The four members of SOB x RBE are from Vallejo, California, home to the iconic rapper Mac Dre. And like Mac Dre—both back in the ‘90s and later, at his thizzed-out zenith—SOB x RBE can be, in the bones of their songwriting, contemplative and grim while making music that’s constantly propulsive, punishing, joyous, fun. Dre would rap over the phone from prison about police brutality and about babies born addicted to crack, but he was doing it with a sort of bounce and levity. It was heavy, but it wasn’t.

SOB x RBE’s latest album, Gangin, follows this lineage, an irresistible record full of songs that hit your gut and your shoulders at the same time. The group (the “x” is silent) was formed when friends Yhung T.O. and DaBoii—who cut their teeth by rapping into their phones and putting it over a beat through a Playstation—fused their efforts with fellow teens Slimmy B and Lul G. The “SOB” is for “Strictly Only Brothers,” the “RBE” is “Real Boi Entertainment.” They’ve spent most of the time since that 2015 merger as a minor phenomenon, both in the Bay and online. Just weeks ago, when Interscope rolled out the TDE-helmed soundtrack for Black Panther, one of its highlights was the skull-rattling “Paramedic!” where each SOB x RBE member bounces his voice off of Kendrick Lamar’s.

About the voices: Yhung T.O., the group’s potential breakout star, is slick and melodic; Slimmy B is an abrasive counterpoint, force to T.O.’s finesse. At some point in their formative stages, the members decided to play with the structure and lineup of each song: Instead of shoehorning all four onto every track, they appear in a variety of orders and combinations, both here and on last year’s lean, self-titled mixtape. This has allowed for Lul G to excel in spot duty, and for DaBoii to develop into a magnetic presence, as brash as Slimmy and with just as much bite to his voice.

This fluidity lets Gangin weave in and out of different sonic lanes without feeling perfunctory or out of place. “Anti Social” is as silky as “Can’t” is confrontational, but the progression from one to the other sounds like a good DJ mix as opposed to an A&R-mandated box-check. The quartet’s youth, their relatively short time rapping together, and commitment to each hairpin turn in tone lends their music the feel of experimentation and discovery and in real time.

That’s good, because there’s a certain breathlessness that their style requires. SOB x RBE fit comfortably into Vallejo’s rap lineage, which includes pioneering stylists like Dre and E-40, and peers like Nef the Pharaoh—whose music seems to be in constant conversation with his city’s forefathers. By contrast, SOB x RBE’s music is less lyrically referential to those predecessors, instead looping back to the lush, up-tempo production traditions from Vallejo and Oakland. As vocalists, they draw obvious inspiration from Detroit’s street rap scene (see: Doughboyz Cashout), though that comes across less as imitation and more as the sort of cultural exchange that has long run between Bay rap and rap in the Midwest and South.

The heart of Gangin is a four-song run on the backstretch where each member is allowed his own solo cut. DaBoii’s “Paid In Full” is almost comically no-frills, and reveals him as an acrobatic technician; “The Man Now” casts Lul G as a villain, sneering and Grinch-adjacent; “Y.H.U.N.G” relocates T.O. to an undisclosed Caribbean villa.

The real jewel is “God,” where Slimmy raps uninterrupted for more than two minutes—it’s not exactly in prayer, more like an explanation to some unseen third party about why he might be praying. There are benedictions for piles of money and humble requests for more; there are hopes for healthy sons and mothers. From there, the song shifts its focus outward, and Slimmy lashes out at some of those who have hurt him. There’s his friend who stole from him, and his father (”I love your ass to death, but don’t ever think I owe you”). The whole thing happens at a brisk pace, stuffed with asides like, “Niggas dying every day, who the fuck this shit fun to?” What makes “God” so arresting is how it reveals the ghosts chasing and invisibly shaping Slimmy’s writing—that just below the surface, torturous thoughts like this are always simmering.

All four members of SOB x RBE let shards of this world-weariness cut through, and to the audience, it seems to bind them together: Not only is there a powerful musical chemistry, but these four redeem one another in perpetual motion as they sort through anger and frustration and wild ambition with a three-man safety net beneath them. It helps that they are all outrageously colorful writers who give the music an overwhelming kinetic energy. They breathe deep life into music with young lungs. Gangin is not explicitly a record about platonic love and the irreconcilable tension between youth and mortality, but it’s that, too.