I took a vacant seat in the front row at the "Fiorello!" opening at TimeLine Theatre on Thursday night. Might as well get close enough to smell the sweat of Tammany Hall.

Fiorello H. La Guardia, the legendary mayor of New York City, was about 5 feet tall. And in this consummate Chicago-style musical production, he rails against corruption and injustice about 5 inches away from the paying customers.

Anyway, I'd seen the show before from a more traditional vista. Nick Bowling's highly inventive 2006 production of this Pulitzer Prize-winning 1959 show from the legendary team of Jerry Bock and Sheldon Harnick (best known for "Fiddler on the Roof") was the biggest hit in the history of TimeLine, the fervent little theater on Chicago's North Side that has enjoyed some explosive growth in recent years. A lot of people were turned away.

So, in honor of both the election season and good business, "Fiorello!" rides again. And he does so with considerably more intensity, certitude and tunefulness.

It was always clear that Bowling and his set designers Kevin Hagan and Mike Tutaj had created a remarkable living sculpture in TimeLine's black box. The 16-person cast of "Fiorello!" is crammed into what looks like a fusion of tenement and law office—a mountainous urban melange of sawdust, desk lights, fabric and staircases. And the proximity to the action makes Bock's intensely melodic score really pop—jolly, harmonic songs of graft and influence such as "Little Tin Box" and "Politics and Poker" snap here in the most satisfying and enjoyable way. No wonder Harnick himself had shown up to see the show again.

But when I first saw the show, I felt that the singing was a good notch below the staging. Not so much this time. That's partly because some of the cast changes—such as the addition of Andrea Prestinario as Thea and Donica Lynn as Mitzi—have greatly upped the musical ante. But it's also because the mostly original cast has raised its game. The likes of Rebecca Finnegan and Terry Hamilton are better than ever.

The head of this talented heap is PJ Powers, who has grown immensely in the title role. You can watch a young actor for years and then, all of a sudden, get the sense that he has just changed into a mature and crafted Chicago player before your eyes. That's what happens here with Powers—he's older, more intense and passionate and, well, suddenly a whole lot better.

Now, "Fiorello!" has the actor to match the outsize personality of the role. Reason indeed to run again.

•Disney Theatricals announced Wednesday night in New York that Ashley Brown, the original Broadway star of "Mary Poppins," will be coming to Chicago in the show's title role.

The famous nanny flies into the Cadillac Palace Theatre beginning March 25, 2009.

cjones5@tribune.com

"Fiorello!

When: Through June 15

Where: TimeLine Theatre, 615 W. Wellington Ave.

Running time: 2 hours, 45 minutes

Tickets: $25-$30 at 773-281-8463