Left to right: Tom Thump, Damon Bell, and DJ Centipede of Friday weekly Loose Joints at the MakeOut Room

PHOTO BY KEENEY + LAW

One of the most influential, and underreported, trends of San Francisco nightlife in the past few years has been the feisty reinvigoration of the jazz scene. Yoshi's Fillmore, which opened in 2007, finally seemed to settle into its giant digs in that historic district — and, despite fears to the contrary, didn't crowd out the stellar, more established jazz joints around it like Rasselas and Sheba Lounge. It also helped expand the traditional jazz palate into famously funkier territory — this month at Yoshi's boasts the Ohio Players, The Family Stone, War, George Clinton and Parliament Funkadelic, and Public Enemy with a live band. (What, no full orchestra? Flava Flav needs some glockenspiel.)

Also recently, San Francisco sent its huge and hip Jazz Mafia collective around the country performing uptempo "hip-hop symphony" Brass, Bows, and Beats. Unfortunately the Mafia's homebase, Coda, closed on the first of this year — along with another beloved club, Triple Crown — citing the economic climate, but the supper club valiantly kept true to its live jazz mission to the end and shimmied with packed aficionados. Club Verde's spunky Tuesday Night Jump! (Tuesdays, 9 p.m., $12. 2424 Mariposa, SF. www.oldtimey.net/tuesdays) with live band Stompy Jones revived that classic SF rockabilly swing vibe. Meanwhile, over at Martuni's piano bar (4 Valencia, SF. 415-241-0205) near the Castro, a new generation seemed to discover its inner Sondheim, tipsily belting a few out 'round the gleaming ebonies and ivories. Send in those damn clowns already, Jesus.

That jazzy hometown spirit of expanding definitions and embracing the musical past as a living thing, not just some retro curiosity frozen into easily marketed poses, has graced other scenes as well. Even as you're funking hard on the floor to some old school disco cuts or electronic productions, it's hard not to hear echoes of jazz's open-minded complexity working somewhere in the background.

And one of the parties I've funked hardest at lately has been Loose Joints (Fridays, 10 p.m., $5. MakeOut Room, 3225 22nd St., SF. www.makeoutroom.com). Let me be clear: Loose Joints isn't a jazz club — although on a recent visit, DJ Tom Thump expertly melted London all-horn ensemble Brassroots' 2010 New Orleans-leaning version of Inner City's 1988 Detroit techno classic "Good Life" into Bill Withers' Hammond-driven soul stomper "Harlem" from 1971. (At that point along my night's journey, I needed a new pair of hotpants.) It's more of an improvisational, all-vinyl DJ jam session that uses classic funk as its departure point. Hitting a tuneful sweet spot neither too familiar nor too abstract, Loose Joints has one of the best brain-to-feet ratios in the city: music nerds will dance their tight glasses off, straight-up partiers will discover where all those groovy samples come from.