Their music changed pop history, but we've never known much about the people who made it...until now. "...the musical trajectory of Sly & The Family Stone, and especially its namesake and leader, Sly Stone (born Sylvester Stewart), makes even the most shocking episode of Behind the Music look like Nickelodeon programming. Esteemed music journo Joel Selvin chronicles the good, the bad, the ugly (and the really ugly),...