OBC, no question.
Aside from the fact that the actual Broadway singers are immensely more talented than the dubbers, the OBC has some of the music the movie is missing, like the ballet, the effed up orchestrations, and for your purposes, Riff sings the wrong song.
"wow I've never seen a production with the dream ballet, it sounds beautiful...how can they cut something that important from so many productions? hmph."
I remember reading something about Robbins even admitting it wasn't perfect...let me take a glance through my Making of WSS Book to see if it's in that one...
Nope, must have been one of the numerous WSS books I've read from libraries, but it was something about Robbins feeling insecure...I think particularly about the schirzo which is the part that occurs right before Somewhere, where Maria and Tony are running and searching to get away from everyone...can't remember anything more specific.
But, here's what the book says about the ballet, mainly quoting the libretto's description:
"Tony expands their wish-fulfillment fantasy into the opening verse for 'Somewhere,' which is sung as a dream ballad and accompanied by a ballet. As he sings, 'the walls of the apartment begin to move off, and the city walls surrounding them begin to close in on them.' Then choreography becomes highly expressive of the intristic drama behind the emotions: 'the two lovers begin to run, battering against the walls of the city, beginning to break through as chaotic figures of the gangs, of violence, flail around them.' They do break through, and suddenly they are in a purer world -- one of 'space, air, and sun.'
This startling transition to a sun-basked innocence in soft pastel colours produces a mood of warm joy. This is the first time that we actually see the sun in the story, and this 'miracle' is celebrated by a gentle love dance to an offstage female voice's singing of 'Somewhere.' The particular lyric of this song articules the lovers' optimistic belief that they will find 'a new way of living' and 'a way of forgiving,' but the very fact that there is as no yet identifiable place or time for such a blessed existence imbues the dream moment with poignancy. Just as the lovers succeed in prompting the rival gangs to join in a winding procession through a 'would-be world,' there is 'a dead stop.' 'The harsh shadows, the fire escapes of the real, tenement world cloud the sky, and the figures of Riff and Bernardo slowly walk on. The dream becomes a nightmare; as the city returns, there are brief re-enactments ofr the knife fight, of the deaths. Maria and Tony are once again separated from each other by the violent warring...they can not reach each other.' There is chaotic confusion and blackness before 'they find themselves back in the bedroom, clinging to each other desperately.'
This dance is also really important to Broadway history, as its the first that the actors playing the characters are allowed to participate in the dream ballet--remember Laurie and Curly are replaced in their dream ballet. This was due to as much Carol Lawrence as Jerry Robbins, because Carol was a ballet dancer and she kept telling that to Jerry, who initially had replacement Maria/Tony dancers, but he finally relented and allowed Carl and Larry to dance it.
So why is it cut? The only reason I can think of is that some people may feel that it's not necessary to the story, at least on the surface level, that Somewhere expresses the sentiment needed on its own. And I guess if they can get rid of one of millions of incredibly hard dances scenes, they do? I mean at one point Maria and Tony are carried off, and one day Carol fell, and was in serious danger of injuring herself, maybe productions don't wanna take this risk?
It's terrible that it's cut, because it's certainly essential to the show on just a slightly deeper level. Dancing aside, Bernstein's music for this sequence is brilliant, and the musical transition from the dream world to the nightmare is just...amazing. And Somewhere is the leitmotif integrated most into the score, arising from the Maria melody by lowering the first note a half-step, and is hinted at and heard in almost all of Tony and Maria's songs, and if everything aside from Somewhere is cut, than the ending of the whole sequence is lost, which is very important, as it juxtaposes the original "ri-a" melody with the "Some-where melody," and the sequence ends the exact same way the Balcony Scene did, and the music that ends the entire show. It just disturbs some of Bernstein's beautiful connections and parallellisms.
And yeah, the dance is probably good too
(Forgive me, I recently got to write a 17-page paper on Bernstein's score for WSS.)
"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