I have yet to watch the movie, but here is my encounter with its theme music more than **20** years ago, in China!
I first heard the music from my university radio station in the early 1980's. I was attracted to it immediately --- the music (no words) was so beautiful and so touching to the young minds. And the good thing is that the station broadcasted it once every day for a long period of time, as the signing off music. That was very appropriate because the ending of the music is vey gentle, fading gradually, like a wind drifting, drifting, until it disappears in the horizon.
At that time, I didn't know who wrote the music, or which country it came from, I even didn't know its title! And the strange thing is that, after I graduated, never once had I ever heard the music again!
Recently I found I have to try hard to recall the melody. So I took my rescue effort: I sang pieces of the music to a librarian in my local public library, who kindly helped me find the music. Only then did I know that the song is calld "A Summer Place"! and it's a love song!