Birdman isn’t the center of attention on the Rich Gang mixtape, but let’s take a moment for Birdman anyway. For someone who, at least according to conventional wisdom, cannot rap, Brian “Baby” Williams sure has verses on a lot of classic songs. “Big Ballin’,” “#1 Stunna,” “Bling Bling,” “Shine,” “Get Your Roll On,” “What Happened To That Boy,” “Stuntin’ Like My Daddy,” “We Takin’ Over” — the Birdman verses might not be the moments you remember best from these songs, but they’re there. On top of that, you can make the argument that Birdman is the greatest A&R in rap history. Lil Wayne and Drake and Nicki Minaj are all transformative rap stars, people who have remade the genre in their own images, and they all owe Birdman their career in one way or another. That’s not even mentioning the late-’90s moment where Birdman and his brother Slim took a mob of New Orleans rappers even grimier and more impenetrably Southern than the No Limit roster and made them even more popular than the No Limit roster, all while rapping over beats that sounded like what would’ve happened if the alien garbage snake from Star Wars tried to make Detroit techno. Birdman barely raps at all on Rich Gang: Tha Tour Part 1, and he mostly limits his on-mic participation to ad-libs and inspirational money-talk montages. (The tape-opening minute-long tirade — “That Rich Gang lifestyle: marble floors, gold terlets, and chandeliers” — is Peak Birdman.) But his real significance on the tape is this: He’s taken two relatively fringey Atlanta cult-rap weirdos, and he’s presenting them not as if they’re rising voices but as if they’re massive stars already. And because he’s Birdman, you believe it.

Rich Gang: Tha Tour Part 1 is really a collaborative tape from Young Thug and Rich Homie Quan, and as such, it’s one of the best mixtapes we’ve heard all year. The context is pure abundance. These two guys, both on furious creative hot streaks, go back and forth for 20 songs, with no skits and no throwaways, nothing but fully-formed emotive melodic bangers. Thug and Rich Homie both get plenty of solo songs, but the best moments mostly have the two of them going back and forth, balancing each other’s excesses, displaying the kind of on-record chemistry that we rarely hear anymore. Thug, who has a peerless ability to prey on the rap internet’s pervasive sense of gay panic, has called Birdman his “lover” and Rich Homie his “hubbie” on Instagram. And even if he didn’t mean that they’re having sex with each other — or hell, even if he did, I don’t know — it’s clear that these guys love rapping together. When Thug is rapping, you’ll often hear Rich Homie’s low moans deep in the mix, harmonizing. Those Thug verses don’t necessarily demand harmony, but somehow they always sound better, just as Rich Homie’s verses sound better when Thug’s electric-shock-yip ad-libs intrude. Every once in a while, they’ll trade off lines, Run-DMC-style, and that’s just the best. Thug raps better than he sings, but it’s still fun to hear him sing. Rich Homie sings better than he raps, but he’s still a very good rapper, and anyway he’s usually doing both at the same damn time. Thug’s voice is an erratic high-pitched yelp, a constant exclamation point. Rich Homie’s voice is a slurry, bluesy, full-chested croon. They balance each other out, and the combination just works.

Thug has had a triumphant but confounding 2014. He’s catapulted to cult stardom on the back of a couple of great underground singles. He’s an in-demand guest. The never-more-stratified rap internet cannot stop arguing about how brilliant and/or gay he is. But he’s also been tangled in crippling contract stasis, since he made the unwise decision of signing to two different labels at the same time, neither of which appears to have his best interests at heart. Most of the new Young Thug music we’ve heard in 2014 hasn’t really been new Young Thug music; it’s been the leftover scraps that he never released when he was part of Gucci Mane’s 1017 Brick Squad roster last year. But now it appears that Birdman has disentangled him, at least partially, from his red-tape bindings, and we finally get to hear what he does when he’s cut loose. On the Rich Gang tape (as on “Lifestyle,” the surprise hit that presaged the tape), Thug raps in a lightspeed melodic croak. He’s not as genuinely insane as he was in his 1017 Thug days, but even his breeziest luxury-life boasts carry the whiff of lunacy. There are moments where he sounds almost exactly like circa-2007 Lil Wayne, and nobody has ever managed to sound just like that guy, even though half the rap world was trying to in 2007. On opening track “Givenchy,” Thug raps like Shabba Ranks if Shabba Ranks was also, somehow, an angry cat. There are moments — plenty of them — where his voice cracks so hard that you can’t quite tell what he’s saying. And while that could be a problem, it’s great for his mystique: “Did he really just say, ‘I gotta see my girl to make my pain real’?”

As for Rich Homie, he might come off even better than Thug on the tape. Less than a year ago, it was possible to dismiss Rich Homie as just another Future imitator who’d scored a big hit out of nowhere but who was careening back toward obscurity. No longer. Rich Homie is more of a rapper than Future, and there’s less of a divide between his singing and his rapping. He sounds casual and comfortable. On “I Know It,” he’s locked-in but effortless, having fun with his shit-talk in a way that he never was before: “I can’t hear what you sayin’ right now, my weed too loud and I know it / I can’t hear what you sayin’ right now, Louis V earmuffs and I know it.” (The relative loudness of weed is a big theme on Tha Tour Part 1; on “Imma Ride,” Thug informs you that “you smoking libraries.”) Thug’s influence on Rich Homie has paid off huge; you can hear it in the giddy, playful cadences he tries out on his verses, sliding his voice in four directions at once rather than crooning straight through the track. But he’s still capable of delivery moments of searing emotional gravity. On “Freestyle,” which isn’t a freestyle at all: “My baby mama just put me on child support / Fuck her, I ain’t going to court / Fuck what them white folks say, I just wanna see my little boy.” Whatever he’s saying, he has presence.

The beats on the tape don’t traffic in the sort of hammering off-ness that characterized past year or so of Thug’s career. They aren’t intense or bizarre. They’re professional. The tape comes with no credits, but judging by producer drops, Birdman has enlisted top-line Atlanta producers like London On Da Track. As on “Lifestyle,” there’s a contented calm to many of the tracks here that we haven’t heard from either Thug or Rich Homie in the past. That’s fine. The danger with fringey artists like this is that they’ll lose some essential part of themselves when they move toward bigger stages. That hasn’t happened here. Both rappers are different now, but they’ve learned how to project their voices without losing sight of the qualities that people liked in them in the first place. In Rich Homie’s case, he’s actually gotten better as he’s figured out how to streamline his approach. They could still lose that focus, as Lil Wayne eventually did. But right now, they’re making personal and singular and excellent rap music on a grand stage, and that will always be a thing to be celebrated.

Here’s why the tape has that title: This November, Birdman and Young Thug and Rich Homie Quan are heading out on tour. They’re playing big stages. Arenas. (The tour is sticking to the American southeast and never going north of Baltimore, but an arena tour is an arena tour.) And given that I can’t envision Birdman doing an hour-long set of Big Tymers oldies, Thug and Rich Homie are the big draws here. That means Birdman has taken two underground rappers, with zero commercially available albums and one genuine crossover hit between them, and built an arena tour out of them. That’s unheard of. But on the Rich Gang mixtape, these two sound like they will belong there.

Download Rich Gang: Tha Tour Part 1 at Livemixtapes.