Musical improv to the letter

An honest-to-goodness champion speller recently got picked as one of the audience participants in “The 25th Annual Putnam County Spelling Bee,” the new musical with the most descriptive title on Broadway.

At every performance, four playgoers are chosen to join the six cast members who play competitive spellers, each with his or her own quirky saga that emerges during the contest. Tony winner William Finn (“Falsettos”) wrote the score for the show.

Director James Lapine and the actors expect the audience recruits to get the easy words. But they were surprised when the ex-champ breezed all the way through “xerophthalmia,” adding five minutes to the running time. The audience loved it, giving the guy a standing ovation after he finally took a hint to “please misspell this word.” (By the way, xerophthalmia means “a dry and lusterless condition of the eyeball ... caused by a deficiency of vitamin A.”)

While such real-time conflict can be electric, it can also throw off the rhythm of a show, says Lapine, who shared a Tony with Finn for the book of “Falsettos.” “Some people get the easy words wrong, so we are out too soon. That can make you crazy too.”

There’s a lot about “Spelling Bee,” this season’s “Little Engine That Could,” that might be considered highly irregular. What started three years ago as an improvisational production that its creator, Rebecca Feldman, describes as “a nostalgic yet twisted take on childhood competition” has made it all the way to the big time.

Feldman’s inspiration was Myla Goldberg’s 2001 novel “Bee Season,” about a young girl speller. “I related to her; she wanted her father’s attention like I wanted my father’s attention,” she explained.