Filmmaking is a visual medium, first and foremost. I don't say that to discount the extreme importance of music (or audio, in general). But just remember why people are watching. Music, though incredibly important, is one of the last things you do.
I agree that many filmmakers believe filmmaking is first and foremost a visual medium and that many also consider music as "one of the last things you do". This false belief is the Achilles heel of so many filmmakers, it leads to so many rejected films and to so many boring and uninvolving films, all the complaints so often levelled at indy films. Even the good silent filmmakers of 100 years ago didn't believe or practice this! And the top filmmakers today would hold their heads in their hands to hear such a thing.
You've mentioned your admiration for Spielberg, he certainly does not practice or believe what you have said. With Spielberg audio is the joint major player, starting at the screenplay and deeply and continuously involved throughout all the phases of filmmaking. For example, the
latest point at which John Williams starts working with Spielberg is during pre-production, same with the sound designer. This attitude and approach (that sound is equally important) is not just true of Spielberg but of Kubrik, Coppola, Scorsese, Cameron, Hitchcock, Leone, Tarkovsky, Ford and in fact virtually every single great director you could mention. In fact, this attitude and approach is one of the major reasons, if not
the most major reason why they are legendary directors, rather than just virtually unknown "also rans"!!!
Film is not primarily a visual medium, it's not even a visual with audio medium, it a medium where audio and visuals are inextricably intertwined to create something greater than the sum of it's parts. All the best filmmakers know this and work towards it from the instant they are involved in the project to the instant they deliver it.
It is an interesting debate but I think the best way for the director to communicate to the composer the music they want varies according to the director. Some feel more comfortable with temp music, others like to just talk style and others there are others that simply want to talk about story and emotion. I've worked with directors who have very specific musical ideas and others who have completely let me off the lead to do what I think best. These are two completely methods that are only good if they give the director the end result they want. Yes it is a collaboration but the director is the big cheese and its up to the composer to bend to his or her needs.
I completely agree this is what happens in practice, which is a shame. Ultimately it shouldn't be the end result the director wants but the end result which best aids the narrative, many directors don't appreciate this and can't separate their personal musical tastes from what is most appropriate for the target audience. I believe that it's the director's job to create the conditions which best facilitates the composer's ability to create the best score possible but in practice directors quite rarely do this, instead they usually try to corral their composer into their own little sheep pen.
G