It was 1969, and Miles Davis, prince of cool, was on the edge of being left behind by a dynamic generation of young musicians, an important handful of whom had been in his band. Rock music was flying off in every direction, just as America itself seemed about to split at its seams. Following the circumscribed grooves and ambiance of In A Silent Way ; coming off a tour with a burning new quintet-called 'The Lost Band'-with Wayne Shorter, Chick Corea,...