I personally like when both the music and the scene astonishes me, and I don’t even know in which of them I should focus my attention. Like everything, a film must be well balanced. Good music used just at the right time will really cause a great effect on the audience.
On the other hand, when the movie is terrible, but the music is good (like some Jerry Goldsmith’s) I’m okay with that since I’d not be wasting my time. (This is not supposed to happen though. Good music for good films = I’m happy)

However, what do you think?

Take Star Wars The Phantom Menace. It may be good music, but given the way the music was chopped up and mixed in the movie, it was a bad movie score.

I don't think the question is with noticing the music, but rather with how distracting it is.

It is hard not to notice the music in the old epic mega movies from the 50's/60's. Somehow, though, that music worked. Many movies have distracting movie scores.

Although in many cases, the problem is not with the composer, but rather with the movie's editing and sound mixing. (Along Came a Spider is one example in which I thought Goldsmith's score worked brilliantly with the images, but the volume of the music was so loud relative to the other sound effects that the music ruined everything else in the movie by calling such strong attention to itself.)

Does a score need to be all droning underscore so that it goes unnoticed and only supports the emotions on screen? Of course not.

The best score is the one that you do notice, but one which does not distract you from the movie's story.

An unfortunate case was with David Arnold's score for Godzilla. It was a rather rousing and well done score, but there was too much going on and it only surfaces a few times. Its a shame too.

Ideally, I think a score should seamlessly blend into a movie and add to the atmosphere. When it is serene, the music should act like a sound effect or character that sets the tone. In a triumphant or important scene, the theme or fanfare should take over the SFX and dominate the audio. This works most of the time, but scores can become so worked into the film that people fail to pick it up.

This is because film is a communicative artform.

P.S: There are a number of problems with that short essay for which Rachmaninov provided a link. First and foremost, it neglects the consequences of film as a communicative artform. The other problems stem from that missing, fundamental premise.

NP Waxman Vol. I.

In the art of communication, the burden rests with the communicator--always. But, an audience needs to be receptive or else it's all for naught. That was my point.

Just as the taste of chocolate is the taste of chocolate, film and music in film are what they are--essentially acts of communication. Realizing that, I enjoy film all the more when I actively engage as a listener and observer.

As for taking your awareness into the films you watch, it is a double-edged sword. For you BD, this may be the best approach to filmwatching, the one in which you personally get the most of out the experience. I can't argue with that, I can only say that just because it works best for you, it still might not be the best approach for everyone.

Here's a very recent example. This morning I watched the 1999 TV film The Crossing which showed on A&E. The Crossing has a score by Gary Chang. In one sequence, troops are standing by just before a surprise attack. Over shots of the men and officers in readiness, Chang resorts to a percussive beat marking time. This is a scoring cliche meant to signify "suspense" and "anticipation". Now, for me, bringing my awareness and past experience into the scene, Chang's approach was transparent, it threw me out of the illusion and put me in that place where my intellect was saying, that's meant to be suspense music. For someone else however, someone perhaps less attentive to form, the suspense signature might have actually worked and helped that viewer feel and experience the emotion that that combination of images and music was trying to convey. In this case, atleast for me, knowing too much or being too aware was a spoiler. But note that I said awareness was a double-edged sword. In watching Triumph of the Will, it's good to know that a lower camera height looking up at a figure will tend to aggrandize that figure and put him in a position of authority in relation to the audience viewer, a state already encouraged by the amplification of image size and position of the screen in most theaters. Considering that nearly every shot of Hitler is taken from this position, if you didn't know how the technique worked, you might come out of the film thinking Hitler is a god, as many Germans must have felt after watching the film in 1934. In cases like this, as in modern cinema (especially advertising), it's best to have your wits about you.

So it's a tightrope walk: too much awareness and you can lose the emotion, too little and you lose your self-protection. I trust that most movies just want me to feel something that I wouldn't mind feeling in the first place (and so I go with them): laughs, tears, a fright, the vicarious satisfaction of some hard to acquire or socially forbidden desire. [Godard: "Movies are a girl and a gun." That is, sex and violence, nude women and blood.]

And that leads me to re-state my position that scores shouldn't be so up front and people might get more emotion out of getting caught up in the fantasy rather than being too aloof.