For what its worth, for me the musical score is almost invisible in this movie, submerged in the background behind the marvellous libretto and the gorgeous imagery. Sure, the melodies are vital and cannot be disentangled from the whole, but again, for me, the music makes no sense without the libretto and the whole glorious visual package.
I cannot actually listen to the suite on its own, I find it almost painful, but when taken as a whole Westside Story is an absolute triumph.