Prince was already an enigmatic superstar before the movie (and soundtrack) for “Purple Rain” was released in 1984. But this outing catapulted him into superstardom — where he orbited the likes of Michael and Madonna (and often surpassed them). “Purple Rain” is Prince at his creative, clever and naughty best. Standard classics like “Let’s Go Crazy” and “When Doves Cry” are teased with gems like “Darling Nikki” and “I Would Die 4 U.” And the anthemic title track is the type of masterpiece by which other songs are measured. The album “Purple Rain” is a bonafide classic. And Prince was just getting started.