“I’m learning as I go,” Will says. “This is everybody’s first rodeo.” Photograph by Philip Montgomery for The New Yorker

At eleven-thirty on a Saturday night, in a bland-looking office building on Sunset Boulevard, in Los Angeles, a security guard in the lobby directed me to a locked door. Hearing the magic words “Mike Will,” the man who opened the door smiled, introduced himself as the studio manager at Electric Feel, and pointed down the hall.

In the main room, the console sat in a kind of sunken cockpit where two producers could work side by side, surrounded by an open hangout space. A long hall led to an internal courtyard, where you were supposed to go if you wanted to smoke, a rule that no one was bothering to observe. There was also a glassed-in conference room, and that’s where I found Mike Will—Mike WiLL Made-It is his producer name; legally he’s Michael Len Williams II—in the midst of a business meeting.

Will is the twenty-seven-year-old founder and C.E.O. of Ear Drummer Records, a label and a production company. His credits include tracks by Kelly Rowland, Miley Cyrus, Jay Z, Kanye West, Rihanna, and Beyoncé—Will co-produced “Formation,” the song that Beyoncé performed at this year’s Super Bowl.

Will’s sessions tend to be loose, free-flowing affairs. At any given time, there are a dozen or more “creators” coming in and out—co-producers (Will has eight on his staff), artists, managers, and hangers-around—contributing to the vibe that is the essence of a Mike Will record: that moment, deep into the night, after hearing the song hundreds of times, when Will gets it and everything goes down.

“He understands the record, he understands the artist, and he understands the idea,” Jimmy Iovine, who was a producer before he became an Apple executive, told me. “Every artist and every song has an idea, and the producer’s job is to capture it.” At a time when a lot of music production is an assembly-line process, Will uses chance, spontaneity, and group dynamics. In his sessions, jamming and messing around—ear drumming, you could call it—lead to happenstance and creativity. He seems a bit like a control freak who understands that control has no useful part to play in the process.

A couple of young white guys in hoodies from 300 Entertainment, Lyor Cohen’s music and management company, were discussing putting together a record deal with Joseph Antney, a Queens-based musician who was signed to Ear Drummer Records as Yung Joey. Antney was there, but he didn’t say much. He kept one palm hovering a half inch over his bare, well-inked abs, occasionally allowing himself to touch skin before pulling his hand back again.

Will sat at a laptop and played a number of Antney’s songs that were in various states of completion. Some tracks included drums and other instrumentation; others were made up of loops with Antney’s raunchy raps on top. Tall and broad-shouldered, Will has a domed forehead, hooded eyes that often wear a deceptively sleepy expression, a closely cropped beard, and a tendency to mumble when he talks. He was in his customary attire: white T-shirt, track pants, New Balance kicks, a gold chain, a jewelled watch, and diamond studs in both ears.

“I feel like he’s a mix of Nelly, LL Cool J, and Fiddy,” Will said, mentioning two artists who are considered not just rappers but entertainers, and the artist and entrepreneur known as 50 Cent. “He’s got that melodic shit, but he’s gonna come out as a rhythmic artist.”

Will talked about the need for an artist like Antney to achieve “separation,” by which he meant the ability to distinguish himself from other performers. “I want an artist to come like Superman”—that is, out of the clear blue sky—“big-ass looks, good-ass music.” He wasn’t impressed by an artist’s twenty million Twitter followers, because “that’s twenty million people who knew you before you were this you.” (In fact, Will is in the process of rebranding the artist formerly known as Yung Joey as X.A.N.—“Xpensive Ass Nigga.”)

Antney grunted in agreement. He looked ready to fly.

“I’m just trying to take the next step with him,” Will went on. “So what’s the next step?”

“Well, I think we really want to get a single together,” one of the hoodies said. “Tonight, if possible.”

That night, Antney was supposed to catch a flight back East, which might be expensive to rebook. Will glanced at the hoodies.

“Let’s do it,” one of them said.

“O.K., so I’m gonna go knock the drums out, that’s first and foremost,” Will said, getting up and heading down the hall to the main room with Antney following.

A hip-hop producer’s personality often shows through most clearly on drums. Mike Will’s drums have a swampy sound that derives from his years of apprenticeship in the basement of his family’s home in Marietta, a suburb of Atlanta. As the artist Big Sean, who has collaborated with Will on several records, put it, “I think his drums are different. They’re muddy, but they hit hard. It’s rare. You can tell from the textures somebody took the time to make sure that the sonics are right, and you got to appreciate that.” In the Big Sean song “Paradise,” which is on Will’s 2014 mixtape “Ransom,” the rapper’s light, skipping flow over Will’s heavy dun-dun-DAH-dun-DAH beat is like the frosting on a molten-chocolate cake.

Drums on hip-hop songs are almost always created electronically, on computers. On a Mike WiLL Made-It track, different drum sounds are combined with other percussion effects, making a dense sonic impasto that stutters and shimmies through the song, until all the elements coalesce for the climax. His beats—the rhythmic and instrumental tracks that form the base for most hip-hop songs—also incorporate melodic elements derived from synthetic keyboards and woodwinds, to give a sense of spaciousness.

Beats are how many hip-hop songs begin; rappers write their rhymes to them. And beatmaking is the way a lot of hip-hop icons begin—Dr. Dre and Kanye West started out as beatmakers. But lots of people can make beats; only a few beatmakers become super-producers.

Will’s productions aren’t instantly recognizable in the way that, for example, Timbaland’s are. Miley Cyrus, who worked with Will on her 2013 album, “Bangerz,” told me, “Mike could lock you in a studio for five days and not play the same beat twice. He has such a library of what he has created.”

In the main room, two producers, Louis Bell and Roofeeo (né Jahphet Landis, the drummer for TV on the Radio), who had come in for the session, were sitting at the console. Will stood next to them, supervising the process of putting drums on Antney’s song.

They began with a snare and a kick drum. The producers would play drum samples from different software files, each barely distinguishable from the next, at least to my ear, but Will knew immediately when he heard the right drum. (“He never ever second-guesses his ear,” Miley Cyrus said.) Within half an hour or so, they had the basic drum sound down and began to work on the instrumentation.

“I want this shit to go rhythmic,” Will said. “Rhythmic and pop. It could be like—what’s that song?” He hummed a little bit of a tune and then, in a falsetto voice, sang, “Oh, baby . . .”