In the 1950s, radio DJ Alan Freed could launch an early rock and roller's career with a single record spin. In the 1970s, Britain's John Peel helped turn artists like the Ramones into stars, one time playing a full side of the record despite (or because of?) his station controller's disdain for punk. As for today, the person with the power to make an unknown artist take off is... an executive at Cartoon Network?

OK, comparing Jason DeMarco, the Vice President/Creative Director of Adult Swim On-Air*, to Alan Freed and John Peel may be a bit of an overstatement, but it's the same concept, albeit on a smaller scale. By striking a variety of partnerships with independent labels and musicians, DeMarco has provided artists with huge amounts of exposure, featuring them during the network's quirky, late-night Adult Swim programming. According to the New York Times, Adult Swim has the highest ratings of any cable network for viewers between the ages of 18 and 49, making it the perfect platform to reach young, music-savvy tastemakers.

These music deals take many forms -- sometimes it's as simple as playing a clip of a song at the beginning or end of commercial breaks (Adult Swim calls these segments "bumps") Though largely unknown at the time, instrumental hip-hop artist Steven Ellison, who performs as Flying Lotus, blindly submitted dozens of tracks to Adult Swim until DeMarco finally bit. Since then, Flying Lotus has garnered heaps of critical praise and has partnered with the likes of Snoop Dogg, Thom Yorke, and Kendrick Lamar.

"[Ellison]’s told me several times that being on Adult Swim is one of the reasons he got noticed and recognized," DeMarco says. "There was a period of time when he was giving me ten beats a week."

But perhaps DeMarco's greatest achievement came when he introduced Atlanta rapper Michael Render, who performs as Killer Mike, to indie hip-hop super-producer Jaime Meline, better known as El-P. The meet-cute couldn't have come at a better time for both artists. Despite appearing on some of Outkast's biggest tracks, including "The Whole World," and scoring a hit himself in 2003 with "A.D.I.D.A.S.," Render had never really broken through to mainstream.

Hungry for a comeback record, DeMarco suggested that Killer Mike hook up with Meline. Meline did more to shape the dark, ragged sound of alternative hip-hop in the 2000s than anybody, producing or distributing through his Definitive Jux label a string of critically-acclaimed records by RJD2, Aesop Rock, Cannibal Ox, and many others. His aggressive production and political lyrics brought to mind early Public Enemy at a time when most mainstream rap fixated on little more than money and house parties.

But Meline too had struggled to remain relevant. His Definitive Jux label was put on hiatus in 2010 and Meline himself hadn't released a record since 2007. As more and more indie kids, guided by Pitchfork's Pied Piper, embraced mainstream rappers like Kanye West and Jay-Z, interest in the brand of outre, experimental hip-hop pioneered by Meline had waned. Both Render and Meline needed a big break, and in each other they found not only an enduring artistic partnership, but a deep friendship, as chronicled by Stereogum's Chris DeVille in a recent profile of the duo.

And DeMarco didn't just introduce the two -- In 2012, he released Killer Mike's "R.A.P. Music," which El-P produced, on Adult Swim's Williams Street Records, a label DeMarco launched in 2007. The album, a crushing twelve-song monster that filtered Render's fierce Atlanta roots through El-P's loud and visceral futurism, garnered the duo more critical and popular attention than ever before. The next year, Render and Meline codified their partnership by calling themselves "Run the Jewels," releasing a self-titled album on Fool's Gold Records to similar acclaim. And just last week, after a summer of playing big festivals like San Francisco's Outside Lands, the duo came out swinging with a sequel to "Run the Jewels" on Nas' record label Mass Appeal, which featured none other than Rage Against the Machine's Zach de la Rocha. According to Metacritic, it has the best reviews of any Render-Meline collaboration yet.

And none of it might have happened had DeMarco not done something entirely unexpected: He launched a record label at probably the worst time in history to do so -- and he did it within a cartoon television network.

The logic behind the move was simple: In an age when even MTV rarely plays videos, Williams Street Records could offer something unique: Television exposure.

"I can reach 2 million people at any given moment who have maybe never heard of any of these artists," DeMarco says. "And it’s a constantly regenerating thing. We’re always picking up new viewers."

Adult Swim still releases compilations of original songs from its favorite artists. And of course, it still features whatever music DeMarco happens to be digging during the "bumps" between shows. But the label has been pretty quiet since "R.A.P. Music." So why did Williams Street slow down after reaching its greatest success? Was DeMarco's thesis, that a network targeting young, music-savvy listeners could launch a successful label, proven wrong?

"For us it was just weird, because we were essentially a boutique indie label inside a giant corporation," DeMarco says. "We really weren’t able to take advantage of either of those things." On one hand, Williams Street was small, and so it lacked the contacts and budgets of an entity like Sony Music -- DeMarco says he only asked for a comparatively small amount of money to jumpstart the label. On the other hand, the size of Turner Broadcasting System, which owns Cartoon Network, limited DeMarco's ability to make non-traditional deals with small artists that would benefit both parties, he says. And even when a success like "R.A.P. Music" comes along, DeMarco is the first to admit that the artist is better off with a dedicated label.

"At a certain point we just discovered we don’t have the infrastructure as a record label to properly promote an artist that gets big enough to make money," DeMarco says. "You know what? Maybe we shouldn’t try to be something that we’re not."

That doesn't mean it's impossible for a bigger network to launch a successful label. "I don’t think another television network is going to do this, but they should. Look at NBC -- they have way more money than us." That said, few of the bigger networks have the same cultural clout as Adult Swim. "No one’s going to think that music on NBC is great because NBC has no musical identity." It could work, however, at a network with a bit more edge like SyFy, DeMarco says.

Just because the record label has slowed down, that doesn't mean Adult Swim doesn't still play a crucial role to promote musicians. Every summer, the network puts out a singles compilation of brand new material from some of DeMarco's favorite artists. This year's collection featured cuts from Future, Deafheaven, Mastodon, and, of course, Run the Jewels.

And most importantly? Adult Swim pays the artists no matter what, whether it appropriates an old song or commissions a new one.

The rise and fall of Williams Street Records is instructive when thinking about the music industry as a whole, and how much value record labels, as they've functioned historically, really offer musicians. Theoretically, the benefit of record labels lies in getting bands promoted and getting bands paid. But Adult Swim can do both of those things without taking on the hassle and responsibility of a full-fledged record label. In turn, Adult Swim benefits from these partnerships by being associated with hip, new bands and positioning itself as a tastemaker. In the same vein as multi-channel networks like INDMUSIC, Adult Swim's one-man music promotion team is yet another example of how bands can reap the benefits of a label without signing their soul away.

As for DeMarco, he's just thrilled to be helping small artists any way he can.

"I want to support artists with money and exposure and help them get bigger," DeMarco says. "In this day and age, it’s one of the bravest things in the world to try to make a living of art in this time and place, and I want to support that."

The music industry needs more guys like DeMarco.

[illustration by Brad Jonas]

*An earlier version of this post referred to DeMarco's position as Vice President of Marketing and Sponsorships for Cartoon Network. That was his old position.