Sylvester Stewart, a.k.a. Sly Stone, thrillingly fused R&B with funk, rock, pop, and jazz as leader of the psychedelic outfit Sly and The Family Stone.  But the visionary artist didn’t emerge from nowhere with his most famous band; he’d paid his dues in the early part of the 1960s at the Bay Area’s Autumn Records label as a producer and artist.  Many of these recordings have been chronicled on collections from Ace (Precious Stone: In the Studio with Sly Stone 1963-1965, Listen to the Voices: Sly Stone in the Studio 1965-1970) and…