Brendan Mulvihill, right, jokes with a friend during a break from the pre-show preparations at The Ox in north Philadelphia on Dec. 11. Mulvihill, 24, lives at The Ox and helps his nine roommates book concerts. Photo by Nick DeSantis

PHILADELPHIA – Winter coats, gloves, and wool scarves are atypical rock concert attire, but Saturday night’s audience at The Ox, an underground music venue in north Philadelphia, had little choice but to bundle up.

Save for a belching space heater and the embers of lit cigarettes, the formerly abandoned warehouse had no heat. The crowd didn’t dance. They happily shivered instead, breathing plumes of fog into the darkness that made it hard to tell the shakers and the smokers apart.

The Ox is one of a large crop of house venues in Philadelphia that eschew the comforts of larger clubs and cater to diverse tastes, from hardcore punk to experimental dance music. Their staffs are permanent; the residents live in the clubs during the week and double as bookers, soundboard operators and clean-up crews. The shows are unadvertised, largely unregulated, and cater to an under-21 crowd that until recently had few options to see independent music in Philadelphia. Together, The Ox and its sister venues carry on a live music tradition in Philadelphia that has flown beneath the mainstream radar for the past 15 years.

Brendan Mulvihill, 24, found the abandoned warehouse that he and a group of friends would transform into The Ox on an Internet real estate site in the summer of 2009. The property’s owner had planned to turn the warehouse into a condo development, but scrapped those plans when the recession hit.

Mulvihill and friends pounced on the available property, turning it into a nerve center for underground music. Behind a false exit door in The Ox’s green room, the group built a kitchen and stuffed furniture into a cramped blue living room.

“We came in with some paint and some silly dreams and just set at it,” Mulvihill laughed.

The story of The Ox’s early days is typical of many of Philadelphia’s underground venues, which are usually located in transitional areas. Greg Johnson, 23, an Ox resident, noted that the cheap rent and large available space would not have been realistic in a different neighborhood or a different city.

“The whole world was freaking out about the economy, but that was the reason this place never turned into condos, so for us it was a good thing,” Johnson said.

The new property came with its drawbacks, though. On the day the Ox residents moved in, Johnson noticed a prostitute servicing a client in a truck parked in front of the building.

In addition to the occasional bursts of crime and the indignities of living in a space that’s short on heat, the residents of Philadelphia’s house venues face a more obvious challenge: noise control. At Danger Danger Gallery, a house venue in West Philadelphia, the residents have piled old mattresses against the living room window to muffle the music. Without the padding, the drums and guitars within would attract the unwanted attention of neighbors and the police.

Tristan Palazzolo, 28, founded Danger Danger in June of 2005 with a group of bandmates from his college days at Temple University.

Danger Danger epitomizes the term “house show.” One of the two front doors opens directly onto a dark stage in the living room. The space barely surpasses The Ox for amenities: its first floor bathroom’s lock is ripped out, with the word “lame” spray painted next to the empty hole.

Palazzolo described the first commandment of house shows in three words.

“Love thy neighbor,” he intoned over sips of beer at the Dock Street Brewing Company, where he works part time when he is not helping organize shows at Danger Danger.

Palazzolo admitted he did not heed his own advice five years ago. After Danger Danger’s first show in June 2005, the venue’s popularity grew steadily and culminated in a three-room, 20-act blowout show in February 2006 dubbed “Aquarius Raging.”

Soon after that show, Danger Danger began to run afoul of a neighbor who tired of the loud music next door, and the group was eventually evicted.

“It was just a matter of time before we got too big for that house,” Palazzolo said.

A friend’s financial windfall allowed Palazzolo and partners to purchase a new house in a retail district just three blocks away, and when Danger Danger moved to its current home in the summer of 2007, the evictions that threaten the lifespan of Philadelphia’s house venues were no longer a concern.

Much like his colleagues at The Ox, Palazzolo chalked the vibrancy of Philadelphia’s underground scene up to inexpensive rent (Philadelphia ranked 40th out of 100 U.S. metro areas in median rent, well behind New York, Boston, Washington, and Baltimore, according to a March 2010 study by the Center for Housing Policy), an abundance of available space, and a willingness to skirt the city bureaucracy that he says makes starting a legitimate business difficult.

A holiday card adorns the sound mixing board at The Ox in north Philadelphia on Dec. 11. The show was billed as the "Holiday Soiree" for the underground Philadelphia venue. Photo by Nick DeSantis

“’No’ is an answer to a question, so if you don’t ask the question, you won’t get the answer,” Palazzolo said. “My thing is, don’t ask questions and don’t ask permission.”

Those bureaucratic obstacles date back to the origins of the underground scene, according to Sara Sherr, 41, a local musician and organizer of Sugar Town, a monthly club night at Tritone on South Street that celebrates women in rock music.

She traced the proliferation of do-it-yourself venues back to the 1980s and ’90s, when Pennsylvania’s liquor laws had a chilling effect on independent music.

Music venues serving alcohol in Philadelphia are required to separate underage patrons from the 21-and-over crowd. Sherr pointed out that clubs profit almost exclusively by alcohol sales, making it impractical for small venues to undertake the expense necessary to separate the two age groups.

Rather than risk the reduced profits of an all-ages show, Philadelphia’s venues of 20 years ago catered almost exclusively to older music fans.

“The divide between the over-21 crowd and the under-21 crowd makes it almost impossible for small clubs to do all-ages shows,” said Sherr.

This hurdle had the unintended consequence of turning Philadelphia into a dead zone for independent touring acts, according to Jon Solomon, a DJ at WPRB-FM in Princeton, N.J., and former host of the Philadelphia City Paper’s “Local Support” internet radio show. Solomon said that many bands avoided the city’s unreliable turnouts, and booked shows in East Coast cities like New York and Washington, D.C., instead.

“For so many years, bands just skipped Philadelphia,” said Solomon. “When I was 18, 19, 20, the Khyber was the only game in town. Now that’s changed, thanks to so many other places where bands can play.”

In response to the dearth of all-ages venues for independent music, young musicians built an organic scene in any rooms where they could squeeze bands, equipment and an audience.

Today, venues like The Ox and Danger Danger have helped solidify the traditions of the all-ages music scene in Philadelphia and ensure its survival even if venues and promoters come and go.

Patrick Rodgers, founder of Nocturne, the city’s longest-running weekly club night at Shampoo in Spring Garden, said this “stubborn insistence” on all-ages shows in the late ’90s and early 2000s helped underground promoters gain prominence and respect.

“A continuity of community is essential to the survival of any scene, and that’s nearly impossible in a 21-plus club environment,” Rodgers wrote in an e-mail. “People need to grow into the habit of regularly attending shows and to feel like they’re part of something that extends beyond the boundaries of a single concert or event.”

After just a year in their warehouse space, Mulvihill, Johnson, and the rest of the Ox residents are already hearing from young music fans that want to follow in their footsteps. A group of Drexel University freshmen has approached them about making plans for their own underground venue.

“You don’t actually expect that people will recognize and respect this, because we’re just doing it because we like to do it,” Mulvihill said. “I guess we don’t consciously think of any glory.”

Inside the heatless, graffiti-sprayed walls of The Ox or the dingy basement of Danger Danger Gallery, widespread recognition seems like a faraway goal for these independent promoters. But the respect of the local music scene is enough to satisfy them for now.

“I go to bed at night and I look at my cinder block walls, and I know this won’t be forever,” Mulvihill said. “But for now, it’s pretty awesome.”