When Marvin Gaye walked onto the Forum floor to sing the national anthem at the 1983 NBA All-Star game, he was in sorry shape. Mirrored aviator sunglasses hid eyes that were red from daily drug use. A lifelong sufferer of stage fright, the former Motown star had tried in vain to get out of the gig. That February afternoon in Inglewood, California, he had arrived so late that Lakers officials were prepared to replace him with an usher.