You know the solo in Van Halen’s “Hot for Teacher,” the one with Eddie wailing away like Mozart on a bender as Alex double-times on his bass drum? Imagine that funked up with some analog keyboards squealing like David Lee Roth if Michael Anthony stepped on his foot, and stretched to infinity. That’s what Billy Cobham’s ’70s sound was like. But as the chopsmaster’s music moved away from intense jazz-rock and fusion and headed for happier jazz-funk, many of his fans lost track of the former sideman for Horace Silver, Dreams, Miles Davis, and John McLaughlin/Mahavishnu Orchestra. Fortunately, by the ’90s, Cobham’s quality control was once again in effect, and the drummer was back—alternating between furious fusion and even some solid mainstream fare. But he had moved to Zurich, Switzerland, recording albums that have mostly made it to the United States through imports or barely registering reissues. But Rhino’s Rudiments: The Billy Cobham Anthology, a two-disc collection that traces the drummer’s mid-’70s Atlantic recordings, is hardly rare. Included in the nicely packaged and annotated set are five tracks from 1973’s Spectrum, a blistering jazz-rock session that ranks with the best of Mahavishnu Orchestra. Cobham is making a rare stateside appearance in support of Rudiments, and he plays with Michael Fath at 7:30 p.m. Friday, April 5, at the Birchmere, 3701 Mount Vernon Ave., Alexandria. $25. (703) 549-7500. (Christopher Porter)