A confluence of recent events provoked me to acquire and watch a copy of the Fox Film Noir DVD of Laura (1944) Included on the disc are some commentary from David Raksin (who scored the film), from film professor Jeanine Basinger, and from historian Rudy Behlmer. Some of these comments add real value, but I was unhappy about things that the commentaries missed, and am thus provoked to write this entry.
Most useful discussion of this film entails some spoilers, and will further presume familiarity with the film. Behlmer strongly urges his listeners to have watched the film with its ordinary soundtrack before listening to his comments. Similarly, I suggest that, if you haven't watched Laura, you stop reading this entry right after I give you just one piece of advice.
That advice is that, while you watch Laura, you dismiss if you can the lyrics that Johnny Mercer later wrote for the theme melody, which impose a new significance to the melody that it wouldn't have had when the film was first made and shown. The melody actually figures within the story (at least in a minor way), and within the story is not about Laura. (By all means, recall and enjoy the Mercer lyrics after watching.)
(Here Be Spoilers!)