When “West Side Story” opened 50 years ago next week on Broadway, its unflinching portrayal of racial discord in 1950s New York resonated with the inhabitants of the city, where as many as 75,000 Puerto Ricans arrived and settled each year in neighborhoods like Spanish Harlem, the Lower East Side, and San Juan Hill, now the site of Lincoln Center.

But the original grit of “West Side Story” has been mostly overlooked in modern times, as Leonard Bernstein’s songs — “America,” “Cool,” “Somewhere” — have become nostalgic fodder for commercials selling khakis and retirement funds. Medleys of the score regularly appear on symphonic pops concerts. Now, in the musical’s anniversary year, there has been a growing debate about its serious origins.

This past spring, the Seattle police department hosted a youth-oriented anti-gang initiative based around the musical, featuring summits on gang violence and a performance of the musical by at-risk high school students. In May, inmates at Sing Sing prison, through a program called Rehabilitation Through the Arts, staged a production of the musical. That same month, a “West Side Story” symposium at the North Carolina School of the Arts looked at how the musical mirrored immigration patterns of 1950s New York.

In the course of researching the show, its director and choreographer, Jerome Robbins, rambled through the dark streets of the tenement neighborhoods. In his efforts to know the social reality of the story, he visited such locales as a gang dance in Spanish Harlem and an Italian street festival in Lower Manhattan where he encountered a brawl between two gangs.

“My office is on Lexington Avenue and 74th Street and just twenty blocks away life is entirely different,” Robbins told Dance magazine in 1957. “The streets are darker, the signs are in Spanish, and the people lead their lives on the sidewalks. Those kids live like pressure cookers. There’s a constant tension, a feeling of the kids having steam that they don’t know how to let off.”

The authenticity of that tension was felt by cast members. “Gangs used to come down and stand outside the stage door and wait to see what the guys looked like,” the actress Chita Rivera, who played Anita, recalled of the post-performance scene outside the Winter Garden Theater. “We used to laugh about it. We were young and foolish. We enjoyed being that close to reality.”

In 1955, New York was home to between 80 and 100 gangs of various ethnicities, and turf battles broke out in neighborhoods from Orchard Beach to Washington Heights. Robbins particularly embraced his research, visiting a dance in Spanish Harlem where two gangs held court, each decked out bright coordinated outfits. He was astonished by the dancing, a soloistic display with minimal contact between dance partners and an air of competitive tension, and this incident helped inspire his staging of the gym dance with its “cha-cha” number.

Robbins was also interested in the psychology of gang warfare, and during the rehearsals at the Chester Hale Studio on West 56th Street, he insisted on keeping the actors constantly in character. The two rival gangs — the Puerto Rican Sharks and the Anglo Jets — were ordered not to fraternize offstage or eat lunch together. Robbins posted tabloid articles about gangs on the cast bulletin board including one that showed the victim of a stabbing in Hell’s Kitchen. Above it he had written, “Read this; this is your life.”

Such fodder, though, is not without its critics today. A professor of Puerto Rican and Latino culture at Hunter College and New York University, Juan Flores, said “West Side Story” damaged the image of Puerto Ricans, whom he said were not any more prone to gang violence than other ethnic groups. “Puerto Ricans were cast in a stereotyped role of gangs and youth violence which often hounds oppressed groups in society,” he said. Mr. Flores added that the heart of the city’s Puerto Rican culture didn’t even reside on the West Side, but rather in East Harlem.

Indeed, as originally conceived by Robbins in 1949, “West Side Story” was to be called “East Side Story,” starring a Jewish girl from the Lower East Side and a Catholic boy from Greenwich Village whose communities clashed around the Easter and Passover holidays. But by the mid-1950s, as the epicenter of gang activity had moved to the West Side, the creators decided to recast their feuding parties.

And even critics did not hesitate to question the work’s authenticity. The influential London critic Kenneth Tynan believed the musical had “an air of sociological slumming,” and wrote that Robbins “probably over-stylized a situation too fresh and bloody to respond to such a treatment.”

But the New York Times drama critic Brooks Atkinson deemed it raw and realistic. “The crafty gangs in ‘West Side Story’ are youths whose speech is acrid and ugly,” he wrote, “and whose conduct is neurotic and savage.”