The beginning of jazz-rock is commonly dated in the late '60s with the emergence of Blood, Sweat, & Tears, the Electric Flag, and Miles Davis' Bitches Brew, but in fact a few sporadic efforts were made at reconciling the two forms before that. The Free Spirits, a New York group featuring the guitar, songwriting, and singing of Larry Coryell, may have been the first. Augmenting the usual guitar-bass-drums rock lineup with the tenor saxophone of Jim Pepper, the quintet's backgrounds were decidedly jazz. But their sound was considerably closer to rock, investing the early psyched...