Like a great conductor, Frank Zappa always ran his bands with uncanny, unwavering precision, and the ensemble he took to the stage of Hollywood’s Roxy in December 1973 made his trademark split-second timing and key shifts look easy. When they stepped out to solo, their virtuosity matched that of any jazz-fusion outfit of the era—not surprising when you look at the lineup, which included such brilliant players as George Duke on keyboards, Napoleon Murphy Brock on saxes and flute, Bruce and Tom Fowler (trombone, bass) and the triple-threat drum/percussion team of Ralph Humphrey, Chester Thompson and Ruth Underwood. And Zappa, of course, is never less than masterful when he plays his guitar. If only he would’ve done more of that, though, and less goofy yapping. Watching the band—all of them good sports for playing along—spill its collective guts during “Echidna’s Arf (Of You),” packed with stunning solos and ensemble work, is to experience jaw-dropping, quintessential musical collaboration. But by this point, Zappa had already let his talky, often infantile, shtick overpower the music. The overly long, set-closing “Be-Bop Tango (Of the Old Jazzmen’s Church)” would have been a gem with the fat cut out, but here, like too much of this intimate club show, it just drags on and on toward tedium.