This arrives early, but it’s worth it: TCM presents this 1968 rock documentary chronicling the birth and explosive presentation of rock music’s big bang. Not the moment of its creation, but the weekend in 1967, two years before Woodstock, in which many of the best minds and musicians of the Summer of Love got together and made beautiful music together. Jimi Hendrix was there, and Janis Joplin, and the Mamas and the Papas, and The Who, and Otis Redding, and Simon & Garfunkel, and