Motown might have been knocked sideways during the early ’70s by the string-driven hit factory that was Philadelphia International, but they were re-energised by the innovations of disco’s prime movers.

Diana Ross enjoyed a career revival herself when she hooked up with the primest of those movers, Chic, for “Upside Down” and “I’m Coming Out”. Rick James, who briefly was going to be as big as Prince, charted with his own Clintonesque sleaze (“Give It To Me Baby”) as well as via his prot