Anyone can do something once. The early announcements on rap blogs, like this one from HipHopDX, were innocuous enough: “After the critical and commercial success of 2012’s R.A.P. Music, Atlanta, Georgia’s Killer Mike and Brooklyn, New York’s El-P are taking it one step further. While Mike already confirmed a follow-up to the album on the Adult Swim imprint, SPIN reveals that for the upcoming works, El-P will be stepping in the vocal booth. Moreover, the pair will be now operating under the guise of a group, called Run The Jewels.” A bit unexpected, but beyond being very good news, that was it. Little did we know that would be the last time either rapper’s name would be evoked before that of their group.

Sudden, middle-aged rap duos had an immediate precedent with the Throne, a moniker under which Jay Z and Kanye West tried to take stock of their tremendous success. Watch The Throne had been a show of force and a glance at isolation, but it never had staying power. A sukkah floating above the desert, it was built to be taken down, and the same was expected of Run The Jewels. But then some producer had to give Mike a beat and say it was the beat of year. That was it. The walls went up, and the two became one.

Like many a rap group before them, much of Run The Jewels’ mystique comes from the fact that they appear to stand alone, iconoclastic, separated from the rest of the game. Kendrick Lamar’s “Control” bars didn’t mention either member of Run The Jewels, and Run The Jewels not only returned the favor but doubled down. “Control” Kendrick became legend for pulling a CM Punk, breaking the fourth wall and making The Game seem tantalizingly real. Run The Jewels operates more like Ric Flair: The Game is obviously a game and RTJ has already stolen the pieces. This self-proclaimed isolationism was only increased through their unconventional release method: albums given away like tapes, with a firm conviction in the melding of new and old. They’d combine non-stop touring with the latest nerd business plan, to give away your core product for free while charging up for bonuses.

That was, as described in Chris Weingarten’s Rolling Stone article, when the realization hit:

“I come out, the crowd, bam,” Killer Mike says. “El come out, the crowd, bam. But then we came out together and there was this other group of kids that went crazy. At first it was just like, ‘Oh shit! Those kids are mighty young to like Killer Mike and El-P!’ And within four or five shows, we started realizing…”

“They don’t like Killer Mike and El-P!” interrupts El with a huge laugh.

What exactly made the two greater than one, and what exactly made Run The Jewels 2 greater than its predecessor? It’s like the difference between a hornet and a whole nest: you don’t want to mess with one, but more feels like an inescapable swarm. This is because Run The Jewels 2, trades mightily on the concept of rap as a form of male friendship. It’s a concept that runs deep within the game, an early sighting being when Eric B. and Rakim commiserated about how angry their girlfriends must be for spending all their time with each other, working on the record. It was solidified, however, by the rappers who would come to define all previous and future rap efforts, a collective that knows a few things about swarming.

Beyond his eerie beats, the RZA’s smartest move was to engineer a deal for the Wu-Tang Clan that allowed each member to pursue their own solo work in addition to a group deal. By removing the incentive for purely financial competition, RZA allowed the group to devote itself to deep contemplation of C.R.E.A.M. The first word of the acronym, cash, offers a motto of its own: e pluribus unum — out of many, one. Listen to 36 Chambers. While individuals let their personalities shine through — you’d never mistake the GZA for the ODB — the underlying star of the album is not a who but a what. A greater entity is felt, be it through the chanting “Wu, Wu, Wu, Wu” of “Clan In Da Front” or the nicknames that seemingly come out of nowhere and that only the rappers themselves fully understand. Something bigger is being built out of the understanding that these dudes have for each other, something that’s nothing to fuck with.

That same feeling can be seen in another of 2014’s biggest rap successes: YG’s My Krazy Life, and specifically its double-platinum single “My Nigga.” If Run The Jewels rotates around The Game with the frequency of Pluto, “My Nigga” did so like Mercury, fast and furious. Its video debuted at MTV’s RapFix. It features hot young guns like YG and Rich Homie Quan and a respected veteran in Jeezy. Its official remix comes stamped with both the Young Money and Untouchable Maybach Empire stamp of approval. Its icy beat was one of many summer smashes for DJ Mustard, but its repetitive refrain stamped its due date well past 2014. Like the words of the Old Testament or the music of Steve Reich, it uses repetition to enforce its bonds: “ride for my motherfucking,” “grinding outside with,” “ain’t going in unless I’m with.” This site declared it “post-hyphy” for the way it exudes energy but never seems to move. When Nicki Minaj jumps over the hook at one point during the remix, she gives it a groove with voice alone. It’s an insular, cocky song, the untouchable part of an album about hubris among other things. It’s YG talking about his friends, but it’s also about him finding them, gaining the acceptance of his peers and elders.

It’s the type of thing to which his and Run The Jewels’ mostly male fan base can relate. Both academics and anecdotes can confirm that male-on-male friendships are, on the whole, weaker and fewer than female ones. A 1980 study on the subject noted that the “emotional relationships men have with other men are weak and absent…In fact, male/male friendships are often limited to formalized settings involving teenage gangs, school, college, work, sports and the military.” Not all that much has changed since then. Directly after college, many guys experience what can be referred to as the Falling Off, in which a healthy social circle shrinks to a microcosm of its former self, despite your best hopes and intentions. As a Salon essay from last year by sociology professor Lisa Wade put it, men “desire the same level and type of intimacy in their friendships as women, but they aren’t getting it.”

In this environment, El-P posting a poorly photoshopped photo of himself and Killer Mike rhyming through a field of flowers on Instagram can feel like fresh oxygen. Or look at the opening banter between the two of them near the beginning of Chris DeVille’s Run The Jewels profile for Stereogum: Call it bullshitting, banter, barbershop, or anything else you want, there’s a distinct sense that these two dudes love hanging out with and appreciate every second they get with the other. Above all that, just look at the music on RTJ2. Look at how often the phrase or some variation on “Run The Jewels” shows up. They can’t stop building it up, creating a mythos without the drag of mythology, just two names shouted forever and ever into the sky.

Wu-Tang laid down two very distinct paths for male friendship. One path was built on shared experiences, namely the poverty and PTSD one could get from living in the poorest parts of Staten Island, and how they can harden your inner circle. This is the path down which YG walks with a terrific and mighty bop. It’s not the most ambitious track on My Krazy Life, but it hits as hard as any of the rest of tracks on that masterpiece do. The other path was built on difference, on how Wu-Tang’s love of kung-fu movies bonded them together. Run The Jewels expands on this idea. When Killer Mike gets blunt police oppression on “Early,” El-P doesn’t try to join in. Instead he paints a picture of a hopeless abyss in which he is powerless to change the system that surrounds him: “Heard it go pop, might have been two blocks/ Heard a kid plus pops watched, cop make girl bleed/ Go to home, go to sleep, up again, early.” It’s a hell of a verse, but it hits even harder because of how it contrasts with the picture of post-Obama BFFs one sees up until that point on the album.

“We know you don’t value my skin,” Mike told a crowd in St. Louis — and, by extension, American society at large — after Prosectuor Bob McCulloh announced that he would not indict Darren Wilson for shooting Michael Brown. “And we know you do value his,” with a quick run over to El, standing next to him in silent unity. “But you know what? We’re friends, and nothing is gonna devalue that.”