NEW HAVEN, Conn. — It’s never played New York, and has neither a celebrity star nor high-profile creators, but “Ella” has become the little show that could, racking up big numbers across the country. It’s the sure thing regional theaters turn to for a guaranteed audience.

In the past four years the biotuner about vocalist Ella Fitzgerald has played at 18 regional theaters across the country and counting, frequently to sold-out houses, amassing total grosses of more than $3 million for its theaters. That might seem like small potatoes for Broadway and its touring offshoots but it’s substantial coin for the regional circuit.

The show’s journey is far from over; additional gigs are set this season at such prestigious venues as the Guthrie in Minneapolis and the Actors Theater of Louisville, Ky. Negotiations are under way for a commercial national tour, with gigs in Europe and Canada also being discussed. As recession blues and the non-profit cash crunch continue to shape subscription seasons toward material with proven crowd appeal, it’s safe to assume the market for shows like “Ella” will not be tapped out any time soon.

New York, however, is still the territory this show has purposely avoided. The unspoken fear appears to be that Gotham critics might not be as enraptured by the show as their colleagues in the hinterlands, and that Fitzgerald’s story might lack the dramatic heft of such other singers as Billie Holiday, Edith Piaf and Dinah Washington.

Conceived by Rob Ruggiero, associate a.d. of TheaterWorks in Hartford, Conn., and Dyke Garrison, with music arrangements by Danny Holgate, the show bowed in 2005 in Hartford, with Ruggiero helming. Originally titled “Ella: Off the Record,” that incarnation was split into an opening act in a recording studio, and a second half in concert.

Audiences loved the show and its lead, Tina Fabrique, who has since played the part in all venues except Chicago and Dallas, where E. Faye Butler assumed the title role. Critics also praised the singer and responded to the music but judged the book to be stilted.

Knowing he was onto a viable property, Ruggiero agreed to further finetuning. Florida Stage commissioned a new book by playwright Jeffrey Hatcher, who structured the show entirely as a concert at a pivotal point in Fitzgerald’s life, with the singer talking directly to the audience. The revamped “Ella” bowed at Manalapan, Fla., in 2006. (Florida Stage and TheaterWorks share in the development royalties in perpetuity.)

“Once Jeffrey came on board the phones started ringing,” says Ruggiero. “For the most part theaters came to us. We haven’t sent out marketing kits or anything.”

After Florida there was commercial interest in taking over the show and touring it with a star but Ruggiero resisted, preferring to continue working on it — which he did for the next two years at theaters across the country, including Cleveland Playhouse, Arizona Theater Company and San Diego Repertory Company.

“Ella” also offered an unusual business model between the show’s creators and the theaters where it played.

Managing directors at regional houses wanting to book the show negotiate separately with the attached talent and creative team. If successful, the theater pays a royalty and gets rights to the show. 

“They need to secure the artistic personnel first,” says Ruggiero of the six Equity cast members. “You can’t buy the production without it. I wanted to maintain the integrity of the show.”

The theater acquires a fully realized production without the costs of weeks of rehearsals, housing the company during that time and building the show from scratch, says Ruggiero.

“The piece is great artistically and it had done well in other markets,” says Jennifer Bielstein, managing director of the Actors Theater of Louisville, Ky., which is presenting “Ella” early next year. “That appealed to us in these challenging times.”

The business model was different than simply booking a presentation. “But we’re always open to untraditional ways of putting on shows,” Bielstein explains. “It does require more work but in this case that’s not a downside.”

Where the creators of many musicals get as much as 14% of the gross, “Ella” gets 11%, with 1% donated to the Ella Fitzgerald Foundation.

“For some of the theaters, the show has broken box office records,” says Penny Luedtke, Ruggiero’s agent who oversees negotiations for the “Ella” productions. “It’s a divine mix of the commercial and the not-for-profit.”

“The creators of the show have not made millions from this model but the theaters have,” says Ruggiero. “In hindsight I kind of wish I’d had better business sense. I walk away with a very small percentage of a very big win. But I’m proud to have provided a financial anchor for many theaters to help them get through some difficult periods.”