You can call it what you want: to me, it is what I would call in Swedish chiefly a Kammarspel.
The concept of Kammarspiele ('Chamber Play') was originally invented by German director Max Reinhard, but it was a concept at once inspired and later more fully developed by Swedish author and playwright August Strindberg in a series of plays written for Intima Teatern (yes, that does mean Intimate Theatre) at the beginning of the 20th century. It was intended as the theatrical equivalent of chamber music; Strindberg even called one those plays The Ghost Sonata.
music which is sung or played by only a small number of musicians, 2-8 people, each with an independent part. Chamber music also involves a more intimate context and close contact between performers and audience, as well as a different way of playing — a sort of conversation between the parts in which none is a soloist but each part has a unique role.
Frankly, I know few ways better to describe Laura. It is a film with a very intimate feel. There are really only six parts: Detective MacPherson; the mordant wit and writer Waldo Lydecker; Laura's rich relative Ann Treadwell; Laura's amoral but charming fiancé Shelby Carpenter; Laura's maid Bessie; and Laura Hunt herself. And they present their story as an ensemble; there are no soloists. Laura herself does not appear in person until halfway through the film, and the role of 'leading man' is exquisitely divided between MacPherson and Lydecker. Most of the film takes place in the apartments of three of them, with the actors in close physical proximity to one another, the camera often lingering on acting performed in conversational tone, with level or deadpan voices, and by small, but important, gestures and facial expressions. Everything is understated but everything matters. Take the scene in which Dana Andrews's character MacPherson asks Laura whether she decided to marry Shelby Carpenter or not (from about 2.59 in the video):
MacPherson: I know that you went away to make up your mind … whether you'd marry Shelby Carpenter or … or not. What did you decide? I want the truth.
Laura: I decided not to marry him.
And then Dana Andrews lets MacPherson smile the smallest of smiles; an almost-smile in which his ear seems to move just as much, or even more, as the corner of his mouth, which merely sort of twitches for the briefest of moments. And yet, with that small smile, and a breath just fractionally deeper than a normal one, Andrews manages to express fully and undoubtedly how happy that answer makes MacPherson.
As a film, Laura works superbly as a straightforward whodunnit. But one of the pleasures of re-watching it (*cough* many, many times *cough*) is to revel in the intellectual jousting between the acerbic, in-your-face wit of Waldo Lydecker and the slyer, less ostensive but oh, so shrewd put-downs of Mark MacPherson. It's so cleverly done. The interaction between these two men has, to me, come to feel like the clou of the film. One of the first things MacPherson says to Lydecker is: You're not the sort of man one would insult, Mr Lydecker. And then he proceeds to do just that with almost everything that he says and does: by not even looking up from his little frame-game when Lydecker explicitly tells him to look at his face: Have you ever seen such candid eyes? The conversion continues and we get:
Lydecker: MacPherson, you won't understand this, but I tried to become the kindest, the gentlest, the most sympathetic man in the world.
MacPherson: [drily, while concentrating on his game] Have any luck?
And when Lydecker, not perhaps entirely at his best, tries to come back with: Let me put it this way: I shall be sincerely sorry to see my neighbours' children devoured by wolves., MacPherson, with a little smile on his lips, almost rolls his eyes at him.
Throughout the film, Lydecker keeps pushing, keeps trying to put MacPherson down by the same means and erudite or sardonic barbs that have supposedly worked so well with everybody else (everybody else but Laura herself, at any rate), but without any luck, save on one occasion: when he sneers that MacPherson is 'in love with a corpse'. But Lydecker himself is in love with that very same corpse: the only way he can rattle and sting MacPherson is to disturb and wound himself too.
Laura is classical Hollywood at its best: a multi-layered story, artfully shot; well and precisely acted and directed. Just like Gene Tierney and the portrait of Laura, it is a thing of beauty.
[*] Do yourself a favour and do not read the Wikipedia entry on Chamber Music in English: it is filled with ghastly expressions such as 'conversational paradigm' and its many, many words provide not so much enlightenment as tedium and excessive eyerolling.