Embrace your inner middle-schooler for a moment and recall a time, long ago, when, in your young mind, the jam band genre represented something truly "alternative" and fascinatingly "indie." Maybe it was the lengthy tracks that lured you in, much like the freaky Lindsey Weir first experiencing The Dead. Maybe it was the likelihood of band members to appear anything but "with it" — mentally, fashionably, you name it. Equally plausible is that the heavy dose of Seinfeld-ian, Zappa-bred bass lines weighing down those noodling, endless guitar bits was your jam-band gateway. Regardless, the only thing that seems to verifiably unite these bands is their general denial of rock radio's standard three-minute format. Sound Tribe Sector 9 hails from college-rock mecca Athens, Georgia, and joined the long-play jam fray in the late '90s, but with a decidedly dub and hip-hop-influenced sound. Carving out their niche in an electronic-funk world, the quintet has put out droves of performance recordings, not to mention studio albums. Their latest, Ad Explorata, is a spacey, trance-inducing work that clocks in at around 70 minutes. Certainly more Four Tet than Phish, the record shows that while jamming seems a relatively simple concept, preconceptions need not apply when listening to music of the jam variety, whatever that might mean.