If Lin-Manuel Miranda had grown up in a yurt deep in Uzbekistan, I am confident that he could have sold investors on a Broadway musical called “In the Steppes.” Had he spent his youth in the Netherlands, audiences might today be tapping their toes to a swivel-hipped paean to international tribunals called “In the Hague.”

But Mr. Miranda grew up in the heavily Puerto Rican and Dominican region of Upper Manhattan known as Washington Heights. And so we have “In the Heights,” a padded, undisciplined, and almost irresistible blend of Broadway sentiment and a pan-Latino sonic hodgepodge of salsa, merengue, hip-hop, and even reggaeton. Along with director Thomas Kail and book writer Quiara Alegría Hudes, the impish composer-lyricist-star has turned this Upper Upper West Side story into, to quote one of the many dance numbers choreographed with street-smart vitality by Andy Blankenbuehler, a “Carnaval del Barrio.” It doesn’t always seem to know where it’s going or why, but it makes the path look awfully tempting.

With the whimsically named Usnave (Mr. Miranda) serving as a tour guide to this “corner full of foreigners,” “Heights” flits among a handful of stories linked by an unclaimed lottery ticket for $96,000. Usnave and his pint-size cousin Sonny (Robin de Jesus) could certainly use the money to spruce up their West 181st Street bodega, but so could Kevin and Camila Rosario (Carlos Gomez and Priscilla Lopez), whose Spanish-language livery car service sits in the middle of a rapidly gentrifying block. (Anna Louizos’s street-corner set and Howell Binkley’s crisp lighting skillfully evoke life in the shadow of the George Washington Bridge.) The rising property values have already ousted the salon run by the brassy Daniela (Andrea Burns, a vocal standout), with the dizzy Carla (Janet Dacal) and the leggy Vanessa (Karen Olivo) in tow.

Usnave’s beloved abuela, or grandmother, Claudia (Olga Merediz), dreams of returning to Cuba, but the only person who has successfully flown the coop — the Rosarios’ daughter, Nina (a slightly stiff Mandy Gonzalez), a freshman at Stanford — may not be able to go back. The only person not broken up by this news is Benny (Christopher Jackson), who has had a crush on Nina since they were kids.

You’ll notice that Usnave is largely absent from this synopsis. As with the off-Broadway mounting last year, Mr. Miranda has turned himself into a fifth wheel in his own vehicle. Usnave carries a torch for Vanessa — an infatuation tested during a superbly choreographed Act 1 finale that challenges the pliability of Paul Tazewell’s costumes — but Benny and Nina shoulder virtually all of the romantic material. And even though Mr. Miranda’s goofy/cute demeanor and ricocheting lyrics (“Let me get an amaretto sour for this ghetto flower”) generate much of the evening’s humor and nearly all of its goodwill, Sonny largely handles the comic relief. Usnave is easily the most interesting thing on the stage, and yet Ms. Hudes allows him to vanish for enormous stretches.

“In the Heights” pulses with a joyful new beat, and youthfulness has its advantages: a fascination with one’s surroundings, a receptivity to the new, an eagerness to share these things with others. From the recent demise of the no. 9 train to the enormous popularity of the Dominican baseball player Manny Ramirez, the story crackles with a deep-grained knowledge of and affection for the neighborhood, and Mr. Kail honors its hubbub by keeping his cast in almost perpetual motion. Youth, however, can also result in a lack of insight into or even curiosity about grown-ups. Despite considerable time devoted to the elder Rosarios and to Abuela Claudia, Mr. Miranda and Ms. Hudes neglect to provide these characters with anything beyond by-the-numbers nostalgia or indignation.

While the older characters are left wanting, the old theatrical and musical styles are well-represented. Mocking musical theater in its more traditional forms has become de rigueur for most pop and rock musicals, but “Heights” offers giddy shoutouts to Duke Ellington, “Too Darn Hot,” and the dancing style of “a drunk Chita Rivera.” This omnivorous generosity, this urge to flood the stage with Big Pun as well as Cole Porter, sometimes gets in the way of the pacing. One-and-a-half songs by the guy who sells piraguas, or shaved ices? Musical mission statements known as “I want” songs for all four of the young leads?

But then Usnave pushes the music into another inviting corner of Latin pop that Broadway had previously ignored, all of it buttressed by Mr. Miranda’s breakneck lyrics and unified by Alex Lacamoire and Bill Sherman’s orchestrations. Usnave loves these sounds and the people who make them: “Everybody’s stressed, yes, / But they bounce through the mess, / Bounce checks and wonder what’s next.” His tour made me think of a much earlier valentine to a New York neighborhood in all its polyglot, harum-scarum, vaguely menacing glory: 1953’s “Wonderful Town.” Leonard Bernstein, Betty Comden, and Adolph Green portrayed the West Village as a bohemian wonderland. Fifty-five years later, Vanessa dreams of moving to an apartment on West 4th Street, one with “exposed brick on purpose, not because the walls were all busted.” Perhaps 2063 or thereabouts will see some ingenue in, say, Yonkers or Camden pining for West 181st Street, which already has a Starbucks and a nuevo Latino restaurant with $35 entrees. Meanwhile, with the deeply flawed and deeply pleasurable “In the Heights,” this town just got a tiny bit more wonderful.

Open run (226 W. 46th St., between Broadway and Eighth Avenue, 212-307-4100).