In an off-brand moment of humility, Flex downplays his role in Jay Z’s success. “He was going to go regardless, he didn’t need me,” he says. But Flex leaning on the record was vital for a song originally released as a B-side. Without Flex’s co-sign, “Ain’t No Nigga” wouldn’t have been the lead single on Def Jam’s heavily promoted Nutty Professor soundtrack in the summer of ’96. Taking a chance on Jay Z was also a low-risk/high-reward move for Flex, who recognized the importance of being a tastemaker. When he debuted on Hot 97 in 1992, he championed new acts such as Black Moon, Onyx, and Jeru the Damaja, knowing that older artists belonged to the previous generation of radio DJs. Listeners would never associate them with Flex. He could never claim them.

Jay Z was a new act who also embodied what Flex loved about hip-hop: bars, hooks, hard beats, street cred. Above anything, Flex, an unapologetic capitalist who has always compared himself to one-named moguls like Russell and Puffy—and not his record-spinning peers—was impressed with Jay’s business acumen, his vision for building a name and a movement.

Flex banged “Ain’t No Nigga,” and then “Brooklyn’s Finest,” “Can’t Knock the Hustle,” and “Feelin’ It.” Jay Z seemed destined to fill the void of slick-rapping Brooklyn hitmaker left following the March 1997 murder of the Notorious B.I.G. But the momentum slowed with the disastrous singles “(Always Be My) Sunshine” and “The City Is Mine,” from Jay’s second album, In My Lifetime Vol. 1. “Trash,” is all Flex says when I mention both records.

“It’s Alright” from 1998’s Streets Is Watching brought him back on board. “Did you hear when I launched that record?” Flex asks, entering raconteur mode. Once again, the sample caught his ear; “It’s Alright” lifted the Talking Heads’ “Once in a Lifetime,” a new wave record from the early ’80s that was also a favorite amongst B-boys and roller skaters in the Bronx.

“Hearing Jay Z rhyme on that record was huge,” Flex says. “As a DJ, that touched my nerve—and the shit he was kicking was hard! I must’ve played that record 30 times in a row.” Top 10 hip-hop singles “Money Ain’t a Thing,” and “Can I Get A” soon followed, and once the blockbuster Vol. 2… Hard Knock Life hit, Hov 97 was born.

Hot 97 was Jay Z’s home for the six straight summers he ran rap. He was featured in the station’s ad campaigns and on-air promos, and performed at Hot 97 sponsored concerts—The Player’s Ball, Hot Night Jamaica, and, most notably, three successive Summer Jams, from 1999-2001, culminating with a legendary set that featured the debut of his Nas dis record “Takeover” and a Michael Jackson cameo.

Naturally guarded, Jay even welcomed a Hot 97 DJ into his inner circle: “As his career started to take off and I’d have him on the show regularly, we clicked as friends,” Angie Martinez wrote. He also regularly played his new albums for her upon completion. Their friendship made for good radio; Jay was at ease opposite Martinez, often betraying his inclination towards reticence. “Angie had, like, the Bat-phone to Jay,” says Hot 97’s DJ Enuff. “I don’t know if they were trying to be a team, but it was definitely a team thing.”

Jay’s bond with Funkmaster Flex was more complicated, a business relationship built on influence and favor. Flex supported Jay, of course. Jay, for his part, contributed to Flex’s albums and made appearances at the Tunnel and on Flex’s show. It was and was not a quid pro quo. “Jay and Flex used each other as tools,” says former Hot 97 DJ Cipha Sounds. “They never clicked. They weren’t friends. They just knew each other’s power.”

Flex’s nightly show was also where Jay turned when he wanted to introduce his new artists. In the early days, Roc-A-Fella had a scant roster: mixtape legend DJ Clue; a ferocious rapper from South Philadelphia named Beanie Sigel; Jay Z’s longtime protégé Memphis Bleek; and Amil, who was dropped from the label shortly after releasing her debut album in September 2000. With the label’s next wave of artists on deck—a handful of Philly MCs in Sigel’s mold—Jay needed a platform. On the morning of January 12, 2001, he called Funkmaster Flex.

Following a conversation between Flex, Jay Z, and then-Def Jam VP Mike Kyser, it was settled: Jay would appear on Flex’s show later that evening, new acts in tow. And though he wouldn’t rap, he instructed Flex to “get the beats ready.” Flex then went for a drive. A car enthusiast, the Bronx-born DJ selected his instrumentals based on which knocked in his automobile. He also braced for the evening; DJing live for artists is different from mixing on the radio. “I’ve DJ’d for artists in clubs, and, um, I’m not very good at it,” Flex admits.

The Roc’s untested squad of battle rappers—Freeway, Oschino, Sparks, and Young Chris—also prepared for a potentially career altering event. Freestyles during Flex’s nightly primetime shift reached audiences beyond Hot 97’s broadcast range. DJs often packaged the rhymes onto mixtapes and compilations, while newfound peer-to-peer file-sharing services such as Napster spread the music online. The freestyles also lived on at Hot 97—a peerless self-aggrandizer, Flex often replayed highlights from his own show.

“I was ready for it,” says Freeway, who had recently debuted on “1-900-Hustler,” a standout track from Jay Z’s The Dynasty: Roc La Familia. “I spent the entire week beforehand getting my bars together. My whole mind frame was: This is my platform, this is the first time the world is really going to hear me.”

The mood was celebratory inside Hot 97’s downtown Manhattan studios on that evening. Freeway and the future members of what would become Philly rap group State Property, along with Beanie Sigel and Memphis Bleek, popped bottles of Belvedere vodka, rolled Backwoods blunts, and rhymed over classic boom-bap productions (Mobb Deep’s “Quiet Storm,” Biggie’s “Kick in the Door,” and LL Cool J’s “I Shot Ya”) for nearly an hour of gripping radio. “It was the spark to their careers,” Cipha Sounds remembers. “Everybody was wondering about these guys afterwards. Everybody wanted to hear more from them.”

Jay Z executed the hardhat duties of a hype man throughout, chuckling at the hottest lines and punctuating verses with cries of “It’s the Roc!” He then thanked Flex and Tracy Cloherty for permitting what was dubbed “The Roc-A-Fella Takeover,” a talent showcase for the label that doubled as free advertising.

“That was a little unusual for me to have a bunch of unknown rappers freestyling,” Flex says today. “I probably wouldn’t have done it if it weren’t for Jay Z.” Because what was good for Jay Z was good for Hot 97—until it wasn’t.

The first strains between Jay Z and Hot 97 manifested in 2001 during the rapper’s battle with Nas. Unlike the Drake/Meek Mill beef, which, for the most part, took place on OVO Radio and social media, Hot 97 owned the moment from when Jay debuted the first verse of “Takeover” at Summer Jam 2001. Surprisingly, though, Hov 97 did not pick a side. Funkmaster Flex premiered Nas’ retort, “Ether,” on December 4—Jay Z’s birthday.

Once Jay rebutted with “Super Ugly,” the station staged a Battle of the Beats-like contest between the two records on Angie Martinez’s afternoon show. “Ether” won with approximately 60 percent of the listener vote. Martinez made the announcement as Jay arrived for a scheduled appearance, and despite the result he stuck around for an interview. He sounded dazed, almost on the verge of tears. “Me, as a guy, I listened to the last verse [of “Ether”] like, wow, like, wow, you know what I’m saying, it’s just, it’s uneasy, you know,” he said. “It’s, it’s, it’s hard, man. It’s very vulgar.” Only Angie Martinez could have scored that interview.

Hot 97 thrived on the conflict. A segment was renamed “The Takeover” in which DJ’s and listeners weighed in on the records and the beef and the insoluble question of who was the better MC. It was good content. Good for business. “Our job was to get ratings,” Cipha Sounds says. “Beef was just a way of getting more people to listen. It was all business.”

Though the tension waned throughout 2002, Nas intended to reignite the beef during his headlining slot at that year’s Summer Jam. He planned to hang a life-size animatronic doll painted to look like Jay Z—there were gallows and everything. When the station refused to allow it, Nas walked. Was Hot 97 finally siding with Jay Z? Did their shared history factor into foiling Nas’ plans? “I don’t think so,” says Mister Cee. “It had to do with Nas bringing that apparatus onstage, that was the concern from the station.”

The fallout was brisk: Nas appeared that evening on rival Power 105, where he dissed Flex, Martinez, and, naturally, accused Hot 97 of favoritism. “You gonna tell Nas, me, myself, what I cannot do on a Summer Jam stage when it’s been done—the same acts have been done?” he said, referring to Jay’s disses from the previous year. “Then I dropped the ‘Ether’ napalm bomb, and their whole crew was running like roaches. And now you got that station over there crying because he lost.”

When Jay appeared on the Angie Martinez show later that summer he had just returned from a European vacation with his new girlfriend, Beyoncé. Known as the “Hovi’s Home” interview, Jay shouted the phrase throughout the interview. He knows a good double entendre when he sees it.

Through the years, as Jay Z transcended rap and elevated to a different stratosphere of celebrity, his appearances on Hot 97 grew fewer and further between. The Angie Martinez interviews started to resemble state of the union addresses. But even as he became alleged text buddies with President Obama, Jay Z still delivered exclusives to Flex. “I made this just for Flex and Mister Cee,” Jay rapped on the 2009 single “D.O.A.” which Flex premiered. “This is for Hot 9-7.”

Off the mic, Jay was also helping out Mister Cee, who he has known since the late ’80s. In 2011, when Cee was arrested for public lewdness after being caught receiving oral sex from a male prostitute, the backlash against him within the industry was swift and harsh. “My financial situation was kind of messed up,” Cee tells me. “I thought: Who could I turn to for some immediate financial help?” He called Jay Z. “I told him I needed some help getting sorted out because a lot of dates are getting cancelled and I got bills to be paid. I never told him how much money I wanted.” Jay told Cee to meet up with his driver, who gave the DJ $5,000 cash. “That’s Jay Z,” says Cee, who left Hot 97 in 2014. “I’m sure if I was in trouble now or if I needed guidance or assistance, he’d pick up the phone.”

In recent years, the relationship between Jay and Hot 97 has withered. Martinez left the station for Power 105 in June 2014, and at this point Hot 97 is regularly beaten by its rival in the ratings game. In January 2015, Flex went on a long rant on his radio show accusing Jay Z of stealing app ideas from him—rap beef in the digital age has come a long way from “That’s why I fucked your bitch, you fat motherfucker.”

“I don’t think there is a relationship,” Flex tells me. “He’s not happy with me because I’ve voiced my opinion on him. The music business is built on phoniness, lies, and how can I control you by making you believe that I’m really a supporter of yours. I learned that I’d rather not sell my soul.”

Flex, who has grown more untethered with age, is also feuding with Drake after accusing the Toronto rapper of not writing his own raps. He seems untroubled by the rift. “I don’t know if Drake is a Hot 97 artist anymore,” Flex says. “Tell me the real difference between Drake and Justin Bieber. Think about it. There’s not really a complete difference, except one artist maybe has more bars—which he possibly doesn’t write.”

Drake hasn’t reconciled with Flex. He doesn’t need to. He has Apple Music. Jay Z might not have much use for Hot 97 either since purchasing the music streaming service Tidal in March 2015. In fact, he hasn’t appeared on the station since an interview with Martinez in 2013. He ghosted on them, as Jay Z sometimes does—ask Jaz-O or Dame Dash.

Next album cycle—and there will be a next album, eventually—how will Hot 97 fit into Jay Z’s promotional rounds? Martinez, his favorite interlocutor, is across the dial. Funk Flex recently called him “a commercial, corporate rapper.” With Tidal reportedly bleeding heavy losses, why would Jay funnel exclusives to Hot 97 and not to his own flagging company?

The answer could be complicated by the fact that Jay still tunes into Hot 97. He was certainly listening on the July morning this past summer when, on the “Ebro in the Morning” show, co-host Peter Rosenberg confronted a caller, a police officer, after the death of Alton Sterling, a black man shot and killed by police in Louisiana. “He emailed Ebro afterwards and told him to give me props,” Rosenberg says. “It’s nice to know that he still hears us as a voice that matters.”