But I rewatch this anime every few years, and simply can't imagine it without this Divine music.

It's true that any good anime, and movie for that matter, needs a good soundtrack and music. Video games, too! If the music is there, and not up to par, it will completely ruin the show.

That Phillip Glass song was really profound. I hit play before I read your paragraph about it, and my immediate thought was that it should be on stage. Interesting that it was intended for a ballet.