you can't tell how good a film is, since thats not even possible after watching the thing. critics may think they're gods gift to the world, but the fact is, every movie affects different people differently and there will always people be disliking or liking one.
but you might be able to determine if its a film YOU'd like. yet probably not just by listening to the music, but watching the intro itself with the music. the intro is part of the movie like everything else, and if it's done in a way that suits you, the same can maybe be applied to the rest of the film.
Anyway, even a few seconds of a movie can often be very telling. When I still had a television I used to zap around alot and watch lots of tv shows. after a while I could recognize my favourite shows in an instant, without even seeing the actors or any other reference points. like matrix has its green pumped up, most shows/movies have a few subtle telltale signs (camera positioning, edited in background noise, music by the same componist, etc) by which they can be identified, from which the coloring/saturation like in matrix is only one of the most obvious, others we don't even consciously detect.
I think i understand now what i have not made clear about my point.... I do not sit and know if each and every movie i watch is good or bad just by hearing the intro music - most movies it is inconclusive. But of the few brilliant movies and crap movies that i see, it is always so easy to identify them just by the intro music. There is something 'instinctive' or 'intuitive' about how i am able to tell a movie is crap from the intro music. And as i said earlier, it is curious to me that if i can tell it is crap just from the intro music, then how come the producers of that crap movie could not see this for themselves? As discussed earlier, possibly a combination of budget pressure and lack of talent?
What you mention about zipping around on the TV reminded me of something i used to do when i was younger.... I used to get a long play video tape (before computers/Internet popularity) and record Rage or Video Hits. Then i would zip through the tape later on and listen to the first second or so of each song before fast forwarding to the next song. I only need to hear about 2 seconds of each song to know it is crap 99% of the time, but not 'crap' actually, yes plenty were crap, but also i was skipping all the ok songs as well.... because what i was looking for were 'good' songs! Once i have found good songs on the tape i will put them on cassette for identification and then buy the album/single. I do similar thing on computer - i just download tons of music then zip through it, and see if anything is good. Typically, if i download 100 songs, i will be lucky to keep 3 of them!
My friends have told me i am quite fussy with music, infact If Earth was about to be destroyed and i was escaping on a spaceship and i was asked to choose all the best music from our planets entire history and fit on just one disk (mp3, not wave) as the only record of music to survive... i would say, "no problem at all, i will be back in five seconds, here you go, and look, there is space left over to fit some games!!