Re: Tony & Maria
As has been pointed out, since West Side Story is based on Romeo & Juliet, Tony & Maria have to fall in love at first sight--it's not even from a musical standpoint, but strictly to keep to the story.
But the composition of the music helps the audience to buy their immediate love. The melody of "Maria" is briefly heard in "Cha-Cha," suggesting Maria's name is already singing to Tony before he knows it. and there's great connections between "Something's Coming" and "Maria." The first 3 notes of "Maria" are the inverse of the first 3 notes of "Something's Coming," but, more importantly, "Something's Coming" ends on an unresolved lowered 7th...which doesn't get resolved into the beginning of "Maria," which starts on a lowered seventh, but then resolves it. This shows that indeed, Maria was what Tony was waiting for at the dance, and suggests perhaps a subconscious connection between them. (For the record, the last note of "Something's Coming was changed in the movie, ruining that connection and pissing me off). Additionally, there's melodic similarities between "Something's Coming" and "Maria." The notes of the phrase "whistling down the river" are inversed to become "Say it loud and and there's mu"(sic playing). So all this music should help to make the love at first sight more believable.
And to those who say they hate West Side Story because of how fast Tony & Maria fall in love, I think that's a shame. WSS is one of the best musicals ever to grace the Broadway stage, and there's so much to love in it, not the least of which is its music and choreography. Even if you can't get past that one plot point, if you go away from teh plot and just focus on the music & choreography, I can't imagine anyone "hating" it.
One more note, I have to agree that Rodgers & Hammerstein did an amazing job with "If I Loved You." It's such a hard sequence, taking two people who just met and convincing the audience that they fell in love by the end of the whole scene. Hammerstein's resolve to turn it into the idea of "IF I Loved You" was just brilliant, and I think it makes you get past the fact that they've fallen in love so quickly. And the way the reprise is brought back, if I loved you, turned into indeed the fact that Billy did love Julie. It's such a beautiful melody.
"If there was a Mount Rushmore for Broadway scores, "West Side Story" would be front and center. It snaps, it crackles it pops! It surges with a roar, its energy and sheer life undiminished by the years" - NYPost reviewer Elisabeth Vincentelli