Just off an alley behind 52 O St. NW, Philippa Hughes is hosting her 42nd birthday party. It is in most respects a typical Philippa party.

The warehouse interior is painted white, marked here and there by artful graffiti. Inside the space, a studio called the Wonderbox, a DJ in a seemingly sprayed-on navy cocktail dress spins top 40 hits—more of them than a warehouse party would seem to demand. A 9-foot-wide roll of thick, black paper hangs from the ceiling, serving as a portrait backdrop for guests who mug for professional photographers.

The night’s event is as much by Hughes as it is for her. This is what Hughes does: She throws Philippa parties. A Philippa party is a mash-up of two endeavors that used to be reasonably distinct: meet-ups for young professionals, the sort promoted by the Going Out Gurus or Things To Do DC or any of the other hype machines she has eclipsed, and DIY art shows, which Hughes has turned into unlikely vehicles for local renown. Since 2007, she has built up her brand, The Pink Line Project, by pushing art, artists, and arts events on a network that has grown to include some 5,000 people.

In some ways this Philippa party is more than typical—it’s redundant. On an improvised platform set between the ceiling and the top of a utility closet, two dancers from a group called the Glade Dance Collective perform. Wearing white leotards, the pair envelop themselves in a stretchy white fabric, thrashing about like a throbbing cocoon. It’s likely that most of the attendees saw this performance back in August at the End of Summer White Party that Hughes hosted at the Phillips Collection. Later, Grammy-winner Christylez Bacon, also fresh from a performance at another Philippa party the previous weekend, will sing a duet with a new singer Hughes has just discovered, Aaron Thompson.

The crowd doubles from 50 to 100 between 8 and 9 p.m. The acts may be familiar, but few of the regulars have been to Wonderbox before. “It’s always a new space with Philippa,” says Jason Bond Pratt, one of the founders of the online art-scenester collective Brightest Young Things. Pratt says Hughes always beats them to the new spots. “We’ll see it and be like, ‘Damn!’”

Which explains why Hughes, in a relatively short period of time, has managed to turn herself into Washington’s most influential arts patron, able to bring out significant crowds in a city whose arts community ranges from lingering DIY types that bristle at society to older, moneyed folks uncharmed by informality. Hughes has gotten a lot of fawning press over the years, and more than a few barbs from people on both ends of the art-scene spectrum who intimate that she’s a lightweight. What she hasn’t gotten, though, is any serious competition for the title of D.C.’s top gallery-party hostess.

Of course, Hughes isn’t the first person to combine socializing with art—and make a name doing so. But while she shares the guerilla aesthetic of predecessors like those around the Decatur Blue and Signal 66 collectives, known for events in the same sort of warehouses as the one where Hughes’ birthday party was held, the Philippa work ethic is more Protestant than punk. And Hughes’ social and economic aspirations are distinctly higher. Her events draw crowds to museums and galleries as well as warehouses and collectives.

In 2007, The Pink Line Project—the formal name (and LLC) under which Hughes throws pop-up gallery shows, art walks, panels, fundraisers, salons and other Philippa parties—hosted 10 events. She did 19 in 2008, adding collaborations with DCist and Brightest Young Things. She nearly doubled the figure in 2009, with 35 events including celebrations for the National Cherry Blossom Festival (“Cherry Blast”) and an after hours party at the Hirshhorn Museum. In 2010, she says she’s hosted 36 Philippa parties to date, about one a week—though she notes she might have forgotten an event or two. She threw a party to open Digital Capital Week, a Mad Men–esque party at the Textile Museum, and a Labor Day soiree at the Phillips.

“Big is important in the sense that it gets attention,” says Hughes, who throws big events. “Getting attention is important. It gives you a platform for saying what you really want to say.”

Hughes is less certain, though, about what that thing is she wants to say. Success has exposed Hughes to attacks from both high and low. She also has the bottom line to think about. She does not draw a salary from her work, and she says she needs for The Pink Line Project to start paying its own way. The lifestyle has taken its toll on her person. In April—a month in which she hosted Cherry Blast and an event at the Textile Museum (“Hapi Hapi Hour”)—within a week of one another, her arms broke out in a rash. Her doctor told her it was stress-induced.