TCM biography leaves questions about Dietrich

You can learn some things about Marlene Dietrich by watching Turner Classic Movies' "Marlene Dietrich: Her Own Song."

1. She had an unconventional marriage, wedded to the same man for decades while mostly living apart from him and having love affairs.

2. She had an intense connection with the soldiers for whom she performed during World War II -- "my boys," she called them -- lavishing them with attention even after they (and she) were no longer young and in uniform.

3. She was strong-willed; told that she could not sing a song in German to an Israeli audience, she responded by singing nine.

These are all interesting facts. But facts alone do not explain Marlene Dietrich -- at least the facts presented by this documentary, which will airs Thursday at 7 p.m. and 10:30 p.m., and twice next month along with 19 Dietrich films to mark her centennial.

Just try to keep your eyes off of her in "The Blue Angel," the 1930 movie that made her a star. Her Lola-Lola is unforgettable, and it is not just fabulous facial structure and a supernaturally husky voice that makes her so.

Or watch Dietrich with Spencer Tracy in "Judgment at Nuremburg." They are like giants; watch long enough, and you will forget the name of every single star in any current movie ("It's George ... oh, you know. In that Sinatra remake ...")

How did Marlene become ... MARLENE?

This documentary, however long (more than an hour and a half) and lovingly assembled (the co-producer is Dietrich's grandson, J. David Riva), does not begin to answer the question. Or even ask it.

Sure, we hear about her upbringing, about the father and stepfather who died when she was young, about her strong, Prussian mother. But then suddenly she is on stage and on the screen, and a success.

These questions remain:

Did she become an American citizen with an eye toward improving her image? Was she motivated to go to the front lines by depression that came when her lover, actor Jean Gabin, joined the Free French?

Her tempestuous life ended in 1992, when she was 91.