Dissonance in Music and Plot

I don't know what other people thought of the music in West Side Story, but I have always thought Leonard Bernstein was a musical genius (he's the guy that wrote the music, but not the lyrics). For one thing, he once played a piano concert on no practice, no sleep, and a night of drinking (he was a replacement, so he wasn't planning on playing a concert the next day), and he played flawlessly. But more importantly, he wrote the music of West Side Story so that it fit the story in an interesting way: he used what's called a tritone. They're sprinkled throughout the score, but the most obvious one is when in the song "Maria." I don't know how much people know about music, but it uses the first note (do), the fourth note (fa), and the fifth note (sol) of a key (so CFG in the key of C). I don't know how much sense that made to anyone, but the point of this is that it causes a dissonant sound. Sort of like the dissonance between the two gangs.