Arthur Laurents, who wrote the original book and was very time-specific back then (setting it in the summer of 1957 when there was suddenly an abundance of rebels without causes), is less specific now in this new version he has directed, omitting the date altogether, hoping for a contemporary reading from audiences since the "social disease" of juvenile delinquency still exists in epidemic portions.

An even more conspicuous change is the bilingual spin he puts on the Shark scenes, turning over his script and two of Stephen Sondheim's songs for Spanish translation by In the Heights' Lin-Manuel Miranda. The original English lyrics to the charming "I Feel Pretty" ("Siento Hermosa") and the charged "A Boy Like That" ("Un Hombre Asi") are printed in the Playbill on the off-chance they didn't play in your head while the Spanish was being sung. A third song, "I Have a Love," which musically bled from "A Boy Like That," reverted to English early in NYC previews.

Joey McKneely, a dancer in Jerome Robbins' Broadway, has the weighty task of "Reproduction Choreographer," recreating Robbins' original Tony-winning choreography, and the great Leonard Bernstein score is robustly conducted by Patrick Vaccariello from orchestrations by Bernstein, Sid Ramin and Irwin Kostal.

"It was an extraordinary experience," a content and collected Laurents was crowing to the press at the elegant after-party held at Pier Sixty. There is, in fact, a book in the experience — "Mainly on Directing Gypsy, West Side Story and Other Musicals," just out (like, March 16) from Knopf. He managed to get in the DC tryout of WSS.

Not one to rest on his laurels, even at 91 (!), Laurents has a new play — a nonmusical called New Year's Eve — opening in less than a month (April 17) at New Jersey's George Street Playhouse, helmed by his WSS associate director, David Saint, and headlining Marlo Thomas and Keith Carradine (both of whom attended the musical's opening). Completing the George Street cast will be Peter Frechette, Natalie Wood's daughter, Natasha Gregson Wagner, and Walter Belenky.

"What was it like to work with Sondheim, and did you think anyone would ever ask you that question?" a reporter asked Miranda. "Nooooo, not in a million years," the Tony winner (for last year's Best Musical Score) shot back with laugh. "Arthur and Steve were both incredibly generous. They told me precisely what they wanted and left me alone. The tricky part was maintaining Sondheim's rhyme scheme in Spanish, which is very difficult. That was very important to him. He'd say, 'I want it to rhyme here, here and here. Everything else, do whatever you want.'"

Miranda also sprinkled sporadic Spanish throughout the libretto. "They gave me a bunch of Latin-American translations [of West Side Story]. I read through them, then chucked them and started from scratch. It was a crossword puzzle."

The Maria of the evening, Josefina Scaglione, had tears streaming down her face when she took her first official Broadway bow. She came out of nowhere — or, rather, Argentina by way of YouTube — arguably, the first Broadway star born that way; Laurents' first sight of her was in a YouTube video and he was intrigued. "Yes, I know, it's crazy," she shrugged sheepishly. "It's a miracle, but those are the things that happen in real life. It's amazing that it happened." She had much to like and relate to about the character. "I came to New York from my country, too, and I speak Spanish, and I know what it is to live in your country."

Matt Cavenaugh has played Tony before — "a few years ago, back in summer stock — but it's great to do it here, now, on Broadway with this terrific cast.

"Josefina is so incredibly real. Y'know, sometimes you just have an inner dialogue with someone. It just happens. You can't rehearse that. You can't make that come to life. It either is or it isn't. And, for Josefina and me, it is. We have a great time."

Another In the Heights alum, Karen Olivo, makes a visceral and passionate Anita and admires her character's arc: "She starts at the top; she ends up at the bottom. There's no way about it. You have to be fiery, and you have to hit the stage running, and you have to knock everything out of the park — every line, every laugh, every button of every number — and, at the end, you really have to deconstruct yourself."

George Akram, who plays Anita's doomed lover, has a big second-act problem — like, what to do with himself backstage. "I put ice on my hand," he said, holding up a cast-encased hand. "I wear a smaller one on stage. This happened during one of the fights last Saturday. One of the ligaments in my finger pulled, and it's injured."

For him, Bernardo was the best and only option for him to play. (George Chakiris, with charisma and hair to spare, got an Oscar for it.) "It's a movie I've watched since I was seven years old. I did a translation of it when I was in high school. I was born and raised in Caracas, Venezuela, and over there we don't speak English at all."

Similarly sidelined from Act II is Cody Green, whose Riff is the first character on stage and the first to buy the farm. "Luckily, the second act is shorter than the first," he noted. "I have a nice long first-act to be in. Sometimes I watch the show a lot. I love this cast. I love getting to watch everyone. Sometimes I work out. Sometimes I watch a little TV. By halfway through the second act, I'm still pretty out of breath."

A survivor of Movin' Out (and TV's reality show, "Step It Up and Dance," for which he was the winner), Green admitted that heading the Jets is a dancing workout. "Obviously, I love it because of the dancing that's in it, but it's everything. It's dancing, it's singing, it's acting. There aren't that many roles like that anymore that really ask you to be a triple-threat, and they go so seamlessly from one to the other. That's the biggest challenge for me from the start of the show — you're dancing, then suddenly you go into a scene and sing your song, and go back into the dancing." Continued...