Every Friday and Saturday night at the McDonald’s at 18th Street and Columbia Road NW, a few things are practically guaranteed to happen. A white guy will walk in wearing a pair of shorts, no matter the weather. A big group of men will order a quantity of Chicken McNuggets so enormous that it tests the endurance of the staff. And at least one young girl somewhere in the place will have a tear-filled breakdown.

“It’s classic late-night Mickey D’s,” says Peter Rosenberg, aka DJ PMD, who on a recent Friday night was planted in one of the restaurant’s booths. Rosenberg watches as the night’s requisite puffy-faced girl stomps up to the restaurant’s top floor to escape whoever has caused eyeliner to run down her cheeks. She is soon followed by a burly blond guy who tries to coax her back downstairs.

As the two talk, rapper O.C.’s “Dangerous” plays loudly in the background. Thanks to Rosenberg, the small-scale human dramas that take place here every weekend now have a soundtrack.

Rosenberg, 27, who lives in Montgomery County, is the resident DJ at the Adams Morgan Golden Arches. Since November, he’s been spinning on Friday and Saturday nights from 1 a.m. until 4 a.m. During his sets, which he’s advertising as a weekly engagement called “PMD Snacks,” he sits in a small roped-off section of the restaurant, playing music and occasionally getting on the microphone to engage the crowd.

His setup is simple, just a speaker system connected to his laptop—no turntables, just iTunes, from which he selects tracks that he hopes keeps heads nodding without making the environment too clublike. Rosenberg’s selections are blasted at a higher volume than the background music at most chain eateries, but he knows that it’s still a place of business—­people have to be able to place orders and talk to friends without shouting too much.

There are speakers both inside and outside of the establishment­—the music plays for those waiting in line, those sitting down and eating, and those just passing by. When people walk inside, depending on how much they’ve had to drink, they either smile upon spotting the DJ or hoot, holler, and walk over to where Rosenberg is sitting and demand to hear their favorite song.

On a recent Friday night, a man in a suit walked in and told Rosenberg the music was “good” but a little too loud. Shortly after, a group of 20-somethings danced their way through the doorway, told Rosenberg his track selections were “awesome” and sat as close to the speakers as they possibly could.

“I love to watch the reaction of people,” Rosenberg says. “To walk into a place as corporate as McDonald’s and hear hip-hop…they’re like, ‘What the fuck is going on?’ ”

Although Rosenberg says he can occasionally be coaxed by a nice-looking woman to play ’80s pop, hip-hop and R&B make up the majority of his playlist—and he tailors what he plays in those genres to suit his audience. “If the crowd is mostly white, I’ll put on some Tribe Called Quest,” Rosenberg says. “If it’s a blacker crowd, I might do some T.I.”

Rosenberg is an experienced club and radio DJ—he has spun at nightspots around the city and has worked at WPGC-FM, XM Satellite Radio, and, most recently, WJFK-FM, where he hosted his own show. But he’s still trying to nail down exactly what people want to hear after they’ve left the bar and are waiting for Big Macs. People nod their heads, maybe sway back and forth a little, but nobody would mistake it for a club: Nobody’s dancing on the counters and tabletops, or grinding on folks by the condiment station.

“I’m still trying to figure it out,” Rosenberg says. “As a DJ, I want people on the dance floor, but it’s McDonald’s. There is no dance floor. There’s trash cans.”

Rosenberg began DJing at the McDonald’s at the request of J.J. Montoya, the owner of the 18th and Columbia franchise. His hope is that Rosenberg’s music will draw customers away from the falafel shops and jumbo-slice pizza joints, which have historically grabbed a huge number of hungry partiers. “He approached me and said, ‘What can I do to get you down here to entertain the crowd?’ ” Rosenberg recalls. “The pizza places kill it on Friday and Saturday night.”

“I walked up and down Adams Morgan and saw kids getting out of the clubs, just lingering around on the street,” says Montoya, who owns four other franchises in the D.C. area. “I wanted to create an alternative, somewhere for them to hang out, meet friends, and grab something to eat.”

After Rosenberg’s WJFK show was canceled last year, he started conducting interviews with hip-hop artists and posting them on YouTube. The McDonald’s gig has inspired a sideline as an MC: Late last month he posted a music video on YouTube for his song “Throw Some Cheese on It,” a spoof of rapper Rich Boy’s hit “Throw Some D’s.” (“Every day I look at a picture of Mayor McCheese on my wall,” Rosenberg raps.)

When Montoya, who was a fan of the DJ’s work, offered Rosenberg a gig that would enable him to bring hip-hop to a corporate monster and confine his entire work week to eight hours, he jumped at it. Montoya initially intended to have the DJ sets end after the holidays, but he was impressed enough with its success to keep it going. “At the end of the day, it’s something people will remember. People walk by and say, ‘That’s the McDonald’s that plays hip-hop!’ ”

Neither Rosenberg nor Montoya would disclose how much the DJ gig pays, but Rosenberg says that his fee is comparable to what his colleagues in large nightclubs around the city pull in—between $200 and $400 nightly. “I’m friends with the guys who [spin] at Love, and I know what they make—­I’m doing just fine,” he says.

Still, Rosenberg was concerned what his friends and fellow DJs would think. He assumed they’d make fun of him. Instead, they’re all impressed.

“I thought people would laugh at me like, ‘Ha Ha! Wack Arnold’s!’ But instead they’re like, ‘How’d you pull off a DJ gig at the most corporate place in America?’ I fuck with McDonald’s,” he says.

The only people who don’t seem to be entirely pleased with Rosenberg’s latest venture are the staff at the McDonald’s (“They want me to play some salsa and merengue,” he says)—and his folks.

“My parents aren’t thrilled I make my money in a McDonald’s and have to drive home at 4 in the morning,” Rosenberg says. “On the Top 10 list of what makes Jewish parents happy, that’s not one of them.”