Through its breeding program for new musicals, the American Musical Voices Project, Signature Theatre had over the past two seasons birthed some promising material: Michael John LaChiusa’s melodically lush, if overlong, “Giant”; and Ricky Ian Gordon’s affectingly personal “Sycamore Trees.”

Every litter, however, is bound to produce a runt, and in the Signature project’s case, that would be “And the Curtain Rises,” the original musical by Joseph Thalken, Michael Slade and Mark Campbell that’s now playing on the company’s main stage.

The story of what’s purported to be the accidental creation in 1866 of the first American musical — an entertainment called “The Black Crook” — “And the Curtain Rises” might have found some traction as an insightful peek at the imaginative process or even, as a last resort, at the timeless juiciness of backstage histrionics.

Instead, the work, staged by Kristin Hanggi, who directed Broadway’s tribute to the radio hits of the ’80s, “Rock of Ages,” comes across as a frustratingly pedestrian affair, with a fairly lifeless score and a book that strings out a rather stale narrative.

That tale revolves for a long time around the struggle between a cluelessly tin-eared playwright (Sean Thompson) and an earnestly educable company manager (Nick Dalton) over the melodrama they’re rehearsing at Niblo’s Garden Theatre in New York. Everyone involved except them seems abundantly aware that the playwright’s “Return to Black Creek” is a total snooze. The opening song, “Someone Must Be Told,” depicts the actors in mid-rehearsal, delivering their own stinging reviews.

“This stinks!” they sing. “Every syllable, consonant: Foul!”

Composer Thalken sets Campbell’s lyric to a jittery rhythm and a Sondheim-esque melodic dissonance. Like much of the score, however, the number lacks finesse. It feels as if it’s marking a space for a better song yet to be written.

Dalton’s nice-guy William Wheatley can’t hear what the actors (or the play) are telling him; he’s an awfully slow learner. So an entire act is consumed with the obvious, that “Return to Black Creek” has got to go, before the inevitable light-bulb moment in which music and dance are added and “Creek” can turn into “Crook.”

In the interim, the theater becomes a refuge, as a result of a fire in a neighboring playhouse, for a corps of French ballerinas, led by the cagey Madame Grimaud (Alma Cuervo). And Wheatley develops feelings for “Black Creek’s” leading lady, Millicent Cavendish (Rebecca Watson), who senses the potential extinguishing of her stardom in the disaster she’s unadvisedly signed on for.

Slade, who wrote the musical’s book, tosses in some other stock characters, such as the company’s warm and cozy comedy couple (Kevin Carolan and Jennifer Smith), as well as a coquettish prima ballerina (Anna Kate Bocknek) who constantly bats her eyes in Wheatley’s direction. In an embellishment that has become all but de rigueur these days, a furtive gay romance is appended, between a burly veteran actor (Erick Devine) and a brooding Hungarian composer (Brian Sutherland).

Cuervo infuses Grimaud with vivacity and theatrical savoir-faire, and Smith is a winning presence as a long-suffering supporting player. A big problem for “And the Curtain Rises,” though, is that the characters always conform to the playbook of established musical-theater behavior, whether it’s Wheatley serenading himself with a pep talk (“Trust Yourself”) or Millicent offering in “Enter Love” her own version of “Before the Parade Passes By.”

Set designer Beowulf Boritt enlivens the evening with a fine rendering of the Garden Theatre’s backstage and some of its period mechanization, and Kathleen Geldard’s bright array of costumes — tutus and voluminous gowns — handsomely conjures the fashion sense of post-Civil War America.

Josh Walden contributes aptly decorous choreography for the ballet dancers. The 14-member orchestra conducted by Boko Suzuki fulfills its assignment admirably, too, even if “And the Curtain Rises” itself never comes anywhere close to a pulse-quickening crescendo.

And the Curtain Rises

music by Joseph Thalken; lyrics by Mark Campbell; book by Michael Slade. Directed by Kristin Hanggi. Sets, Beowulf Boritt; costumes, Kathleen Geldard; lighting, Colin K. Bills; sound, Matt Rowe. With Erik Altemus, William Diggle, Greer Gisy, Suzanne Darling, Kristen Calgaro, Rachel Schur, Laura Keller. About 2½ hours. Through April 10 at Signature Theatre, 4200 Campbell Ave., Arlington. Visit or call 703-573-7328.