On paper, nothing seems sillier. Gang fights set to music. Singing thugs reenacting ''Romeo and Juliet,'' with Puerto Ricans as Capulets and whites as Montagues. ''I Feel Pretty.'' Crazy. And yet, incredibly cool. But, for the sake of argument, don't think of West Side Story as a musical -- think of it as an early, predigital experiment in passionately enhanced reality, the spiritual forefather of ''The Matrix'' and the whole bullet-time culture that bore it. What else would you expect from one of the greatest and most tumultuous collaborations of all time? Jerome Robbins, Leonard Bernstein, and Stephen Sondheim used their shared gift for sheer go-go-go! -- physical, musical, and verbal -- to isolate something sad and savagely wistful in the American character.
Bernstein, in his never-equaled score (like the print, gloriously remastered here), found something in a restless, ever-tilting fusion of jazz, mambo, and Broadway balladry that's as grand and dizzying a distillation of New York City as exists in any medium. Sondheim nailed it with deceptively simple mosaics of hipster monosyllables (''Cool!'' ''Go!''). And Robbins? The codirector-choreographer-dictator certainly inspired strong feelings on set (''I don't think he was really happy with a dancer unless their feet bled,'' recalls Russ ''Riff'' Tamblyn in a spectacular supplementary documentary) and even had to be fired from the production after budgets skyrocketed and cast members dropped from exhaustion. (Codirector Robert Wise -- who would win an Oscar for ''The Sound of Music'' -- with his refined sense of cinema and diplomacy, brought the film in for a safe landing.) But Robbins' vision -- the jagged formations, the impassioned high-kick detonations, the off-balance acrobatics ricocheting off hard urban angles -- set an exhilarating sensory tempo we've been dancing and fighting and bullet-dodging to ever since.
And if all that isn't enough for you, star Natalie Wood's original vocal tracks (mercifully replaced by Marni Nixon's in the final cut) are sampled in the documentary -- in case you enjoy wincing.