“Blank! The Musical” provided audiences with the unique opportunity to participate in the creation of their own musical. Unlike nearby Broadway shows performing the same show night after night, “Blank!” put on a one-of-a-kind show every night from Nov. 1 to Nov. 30. The talented actors, musicians and stage crew worked together seamlessly, devising a completely improvised musical.

Ensuring that the cast and crew had no time to prepare, audience participation did not begin until everyone was seated in the theater. Audience members suggested names for the show, song titles, musical scores, choreography and lines for members of the cast to deliver. Playgoers then used their smartphones to vote for their favorites — all were incorporated into the show.

The results were shown on screens around the theater, creating a lively, interactive environment. T. J. Mannix, the host, explained the nuts and bolts of the show, all while bringing an energy to the stage that paralleled that of a game show host. Once the audience voted, the cast was informed of the show’s infrastructure and immediately began to perform, taking no time to regroup or prepare.

Yet after the voting was over, the audience was able to easily forget that the musical had not been rehearsed. Katie Dufresne, Nicole Hastings, Tessa Hersh, Andrew Knox, Matthew Van Colton and Douglas Widick, the cast of improv actors, collaborated on the spot with the musicians, turning the audience-created titles into songs and building a coherent storyline.

Thanks to the improvisation, “Blank!” had an endearing freshness. The audience caught the cast holding back laughs. And though the cast had no time to prepare for the 90-minute musical that ran without intermission, the fluidity and transitions were impressively effortless.

With a stage featuring two elevated platforms and several modest chairs, it is truly the performers who brought “Blank!” to life. They brought an unparalleled energy to the stage, executing a convincing yet wacky show without an elaborate set. Unafraid to make fools of themselves, the cast sang, danced and interacted with astonishing commitment to the foundation that the audience provided.

On one particular night, the questionably named “Is This Supposed to Smell?” became an actual musical. A complex and humorous plot unfolded, in this case featuring two recent divorcées from Maine and the cab drivers who pursue them while simultaneously involving a wealthy man’s attempt to have a child with a 76-year-old woman and even a group of whales and their dentist.

It is without a doubt the music that was the key element to the success of “Blank!” The musicians — a pianist, percussionist and woodwind player — improvised melodies that made the sometimes-nonsensical lyrics sung onstage seem more meaningful and prepared. Considering that the players were only provided with a four-chord theme at the beginning of the show, their ability to conceive scores that enhanced the improvised singing was extraordinary. It was impossible to imagine the success of “Blank!” without its music.

Laughing continuously for the entirety of the performance, the audience was left with a memorable, one-of-a-kind theater experience. It is hard to imagine how the cast could create such captivating and enjoyable shows night after night, but they delivered. “Blank! The Musical” establishes a place for improv in theater, charming audiences with what was truly a great show.

“Blank! The Musical” ran for a six-week engagement at New World Stages, 340 W. 50th St.

A version of this article appeared in the Tuesday, Dec. 2 print edition. Email Willa Telekson-Flash at [email protected].