If you think your knowledge of musical arcana is peerless, spending some time with the compilations from Chicago’s Numero Group label might take you down a notch. To put together LOCAL CUSTOMS: LONE STAR LOWLANDS , obsessed collectors wore face masks to ward off the toxic fumes emanating from the mold-encrusted tapes amassed by Beaumont’s defunct Lowlands Recording Studio. Housed in a nondescript strip mall, Lowlands nurtured the Golden Triangle’s post–Janis Joplin/Johnny Winter scene, recording late sixties–early seventies bands with names like Mourning Sun and Insight Out. These recordings aren’t polished, but they’re far from amateurish and contain unexpected delights. Circus’s “Give Me Time,” with its overdriven classic rock feel, neatly summarizes the era. Uniting the jammy instrumentals, Southern rock, folky harmonies, psychedelic rave-ups, and flute solos is a shared vibe that comes from a tight, incestuous scene recording in a single location. All these musicians were working hard to make it big, even if for most of them that only meant landing a gig in Houston.