“What’s happenin’ Houston?” It’s the way George saunters off his mothership, rocks his head and taps the handrail, or the guy in the audience passing a joint to the band, or the 30 people jamming onstage at the end: Maceo, Fred, Bernie Worrell, Bootsy banging a cowbell, the Parliaments belting it out – once you’ve seen this you may doubt you’ve ever been to a real concert.