Wow, it really surprises me how many people hate the *Ladyhawke *soundtrack. The Alan Parsons Project isn’t usually a band that gets a lot of dislike. I admit it’s been awhile since I’ve seen the movie, but I remember loving both the movie and the music.
Of course, I’m a hardcore APP fan, so that might help things. 
I recently (last six months) showed Ladyhawke to a mixed group of viewers that had never seen it, most in their late 20’s, early 30’s, anda few teenagers. Every single one of them thought the soundtrack was weirdly out of place and didn’t fit the movie at all, several saying that they couldn’t watch it and take it seriously because of it.
YMMV. 
Author, Author is a completely underrated movie starring Al Pacino, Dyan Carroll, Alan King, Bob and Ray and some really funny kid actors (who I can’t remember the names of) that has this god-awful, movie-of-the-week quality, new-agey, pussified, plinkety-plinkety score to it which all wraps up in the final, over the credits, song called, “Milk and Cookies” (I think) that sounds like it’s being sung by a failed music major on a suicide watch with too many Casio keyboards laying around.
I’ve never in my life seen a movie that was ruined by the soundtrack, at least not that I noticed. Maybe some movies that could’ve been saved by a better soundtrack, but that’s different, right?