In L.A., jam nights these days are often an assemblage of all-star musicians who come together to play the classics, usually prepped with a rehearsal or at least prior knowledge of what they will be performing. They're often stellar-sounding, brag-worthy spectacles, but they tend to lack spontaneity and the organic magic of what a true “jam” can be. But for nearly 25 years every Tuesday, the Kibitz Room at Canter's Deli has hosted an intimate gathering of musicians — calling themselves The FOCKRs — doing it garage-style: throwing out song choices on the fly and inviting their pals to jump onstage and join in. Along the way, this little jam has thrived with its own big-time pop-ins, including Slash, Lenny Kravitz, Rickie Lee Jones, Dave Navarro and even The Pointer Sisters. Many of the FOCKRs rockers play the other jams around town, too, but at Kibitz they're more relaxed, getting to work shit out. Rollicking, raw and in real time, they often play for 2½ hours straight, reinterpreting rock and soul hits both instrumentally and vocally, and keeping the old-school jam concept's element of surprise alive.