When fans of the hybrid tunes known as mashups need their dance itch scratched, they make a boogie-beeline for Bootie, the country’s first monthly mashup party, which turned three in August, or its cozy spin-off, Mini-Bootie, at alternative dance party Pop Roxx. Bootie cleverly gets its name from pirate-speak for stolen treasure, since mashups—bootleg dance remixes created by digitally combining the vocals from one song with music from another—are rarely authorized by the original artists. The widespread popularity of Bay Area mashup DJs and Bootie has earned the city a reputation as a mashup mecca. “San Francisco has just the right mix,” explains DJ Earworm, a popular mashup DJ-producer and Bootie regular. “It’s a really creative city, and it’s a technology-oriented city.”Mini-Bootie 1:45 a.m. THE SCENE Drunk on the party vibe, regulars pack the small dance floor at DNA’s upstairs lounge until they’re given the boot. THE SOUND TRACK Top 40 meets rock riffs. Too-cool alternative types can justify wiggling to a Kelly Clarkson song as long as it’s mashed with Deep Purple and Doobie Brothers and served with a side of Paula Abdul.EAVESDROPPING A tipsy female patron at the bar screams, “Oh my god, this is Ciara and INXS!” THE CROWD Club kids, scruffy queers, glam-fab trannies, and dapper Castro boys share the floor with girls’-night-out groups and beer-swilling straight dudes. Bootie, every second saturday at the DNA Lounge, 375 11th St., S.F., www.bootiesf.com [1]. Mini-Bootie at Pop Roxx, also at the DNA Lounge, www.poproxxsf.com. Elsewhere Bootie’s creators, Adrian & the Mysterious D, post their mashups on their website, where fans can download them for free. www.rebeldjs.com. Mini-Bootie’s resident DJ, Party Ben, besides holding the record for most vodka tonics ingested in one set, is also Live 105’s creative director. www.partyben.com. DJ Earworm, whose how-to book titled Audio Mashup Construction Kit comes out this month, plans to launch a new mashup night before year’s end. www.djearworm.com.