Review: With her widower's help, a splendid new documentary explores Mary Tyler Moore's private side

"Who can turn the world on with her smile?" It's Mary Tyler Moore, of course, and you should know it.

To be precise, it's Mary Richards, a person Moore played. But the smile was her own, and it worked magic across two situation comedies that described their time in a way that some might have regarded as ahead of their time. Although Moore proved herself as an actress of depth and range and peerless comic timing again and again, on the small and big screen and on the stage, "The Dick Van Dyke Show" and "The Mary Tyler Moore Show" made her a star, and incidentally a cultural figurehead, and are the reason we have a splendid new documentary, "Being Mary Tyler Moore," premiering Friday on HBO. Were it titled simply "Being Mary," there'd be little doubt who was meant.

Moore was driven to perform from an early age, which she relates to wanting to impress her father — though