A Spanish-accented Yankee doodle dandy

Their hardscrabble Latino neighborhood at the northern tip of Manhattan is rapidly changing, becoming gentrified. Close-knit families and friends are moving out and apart. The place may not have fulfilled the American dream, but it was theirs. It was home. It was community. And this is the Fourth of July.

As the characters of In the Heights gather for fireworks on their street in the shadow of the George Washington Bridge, the neighborhood is thrown into a blackout.

"We are powerless! We are powerless!" they sing, in an urgent, plaintive refrain both literal and not. On the Academy of Music stage, where the national tour of In the Heights runs through the weekend, their powerlessness is an indelible theatrical moment. The plot calls for a blackout; the audience is electrified.

In the Heights ended its run on Broadway this month, after three years during which it won the best-musical Tony Award and set out early on a national tour. Philadelphia is providing its best week on the road so far. The box-office yield here was just shy of $1 million by Tuesday's opening. I have no documentation but I like to think that Philadelphians, savvy about the theater, are so attracted to the show because American history is in our urban blood.

In the Heights - with a gorgeous cast and a bursting Spanish/inner-city/hip-hop flavor - is American history unfolding without even a simple reference to that dynamic. Yes, it's specific to a neighborhood corner where the elderly and almost all who followed are rooted in countries throughout South and Central America. But it's really the story of new roots, of becoming an American hybrid, of struggling and fitting in and holding back and, ultimately, changing our national face. In that, In the Heights is a quintessential American musical.

The rapid-fire tunes and lyrics, by Lin-Manuel Miranda, are magnetizing. They're often laced with Spanish, and with bang-bang interior rhymes - musical poetry slams. Here, they even survive a major roadblock: the Academy's unforgiving acoustics, which sometimes offer them up as garble. And still you can get everything by context.

If you don't, depend on In the Heights' tight, fluid book by Quiara Alegría Hudes, who began writing plays almost two decades back as a Philadelphia Young Playwrights member at Central High.

The production itself is sterling, with a cast that brings off Andy Blankenbuehler's breathless, kinetic choreography as if it were natural street movement and maintains character through the complex, plot-driven songs. The warmly inviting Joseph Morales plays the orphaned young man who runs the little bodega where, amid coffee and newspaper sales, much of the action unspools. The other major characters - they are numerous - match him in their abilities to immediately define themselves, and then their motivations.

As on Broadway, the Academy's opening-night audience was riveted by the remarkable roads and roadblocks the show details, and gasped at many plot turns. Some will decry that plot for moving forward, and tidily resolving, with unchecked sentimentality - which it does.

So maybe for its characters, its little hopes are misplaced and its convictions unfounded. And maybe not. With its ultimate blind faith, In the Heights summons unchanging core American values and cycles.

As people move from their corner, so do their shops. When a shop sign comes down, you're looking at the sign it had replaced, and at a bygone America with the same aspirations, the same tensions - the same story of moving out, on, and forward. In the end, we are not powerless. We are empowered.