A telephone call comes from your producer, Cameron. He has an empty theatre. Could you send him the first half of a new musical in, say, 40 minutes?

And so begins Showstopper!, the show which creates a unique musical during the performance out of audience suggestions and the dazzling improvisational skills of the cast and musicians. On the night this reviewer attended, the audience voted for a Nashville, Tennessee setting. Title suggestions were canvassed, and the audience chose 'A Tennessee Waltz'. Musical influences were solicited (My Fair Lady, Book of Mormon, Come From Away and Hamilton). Our characters appeared: Jo-Ellen and her lovestruck colleague Tony, Mary-Sue and her Pappy and Grandpappy, and the villain and town big-shot, Mr Jenkins. A story unfolded, discovered in its telling.

With a handful of simple props, augmented by mime, we follow the tale of Jo-Ellen and Mary-Sue's forbidden love and their wish to dance together against societal oppression. With cheeky references to modern musicals, the news of the day and even duff audience suggestions, the slick performance belies the cast's impressive talent. It's hard to believe this is all made up on the spot. The fluid, unspoken communication between cast and musicians - suddenly striking up the next song just when it is intuitively needed, a character interjecting narrated exposition mid-song as the music softens - mean changes in mood and scene are deftly handled. The director, Dylan Emery, is on hand to pause the action any time a fresh direction is required, and to consult with the audience. During the interval, he urges the audience to tweet their suggestions for the second half, and then we vote on the best, sending the story in an unexpected direction. The comic timing is spot on, and the action never flags.

And yet, when you see it, it will be a completely different but no doubt brilliant story.

On a cold night, the warmth and fun of Showstopper! made for a throughly enjoyable evening. Running until 16 March 2019 at The Other Palace theatre, this is a treat for all musical lovers. And if you don't believe every performance is different, they'll even give you a ticket discount so you can see it again.