When Jason Mundo held his first Dub Assembly event two years ago, only about 30 people showed up. But they were all "vibing on it really hard," he says.

Photos by JASON JANIK/Special Contributor

Jason Mundo and Lifted MC play original recordings and remixes, some of which have been released as singles under the Dub Assembly record label.

"A lot of people were dancing, nodding their heads," says Mundo, a Dallas DJ who's a civil engineer by day.

The crowd has since grown fivefold. They're all devotees of dubstep, a genre that was born in South London around the turn of the millennium and has since spread virally into the U.S.

Dub Assembly, Dallas' longest- running dubstep night, celebrates its second anniversary tomorrow with a bash at the Green Elephant. Another local crew, Dub Commission, has thrown monthly dubstep events at Absinthe Lounge for the past year.

At its most basic, dubstep is a style of electronic music laced with a deep, booming sub-bass. The rest of the elements are up to the producer – it can be moody, dreamy, psychedelic, uplifting.

Mundo and his partner Lifted MC like to add a little danceable reggae flavor. Dubstep could also have elements of heavy metal and minimal techno.

Joe Nice, a Baltimore DJ who launched one of the country's first dubstep monthlies in New York, describes the music as "beats + pace + space" on his MySpace page.

"If it doesn't have bass, you're wasting your time," says Nice, 32. "Good dubstep has that release and restraint, that push and that pull."

Tomorrow's guest Dub Assembly DJ is Hatcha, one of the pioneers of the sound from South London. Mundo says to come expecting a party.

"The bartenders have told us we've knocked some bottles off the wall," he says.

Dub Assembly's second- anniversary bash is tomorrow at the Green Elephant, 5627 Dyer St. On the bill are Hatcha, Mundo, Lifted

MC, Keith P. and Royal Highnuss. Doors at 10 p.m. $9. myspace.com/ dubassembly.

•dubstepforum.com –Comprehensive Web site with dowloads, event listings and chatter from the dubstep community worldwide.

•myspace.com/dubcommission –The Dallas dubstep crew hosts a monthly event at Absinthe Lounge, and are regulars at Pasha Nights, a monthly event at Minc. They can also be heard Tuesdays from 6 to 8 p.m. on subfm.com, an Internet radio station.

Nice describes it this way: The human heart beats around 60 beats-per-minute. Most house music is around 120 bpm. Drum n' bass is usually played around 180. Dubstep is right in between the two, at about 140. "It's a little faster than house, a little slower than drum n' bass, but there's still that feel that you can get with," he says.

Check out QuickDFW.com for a list of 10 dubstep artists that novices should check out, courtesy of Joe Nice.