“Something’s Afoot,” Pioneer Theatre Company, through Oct. 5, $42-$65 in advance and $5 more on performance day, 801-581-6961 or pioneertheatre.org

A crash of lightning, a sequence of ominous organ chords, chandelier lights flicker and one of the 10 guests invited to the stately English manor suddenly drops dead — and “Something’s Afoot.”

To open the 2013-14 season, Pioneer Theatre Company artistic director Karen Azenberg selected a little-known musical comedy/murder mystery mash-up and stages the production so expertly with an exuberant cast to make “Something’s Afoot” tremendously entertaining live musical theater.

“Something’s Afoot” is sure to delight the passionate theatergoer anxious to be taken by surprise with a genuine discovery, but also the casual patron who only ventures away from TV channel surfing on his well-worn couch for light and breezy fare.

The title sounds as if the show could have been penned by Agatha Christie, but it’s a wholly originally twist on the novelist’s popular thriller “Ten Little Indians” (and its film version, “And Then There Were None”) with brief allusions to Sir Arthur Conan Doyle and Mary Roberts Rinehart, who inspired the phrase “the butler did it.”

You don’t have to know the genre, but if you do, there’s more to savor. Yet at the same time, the plot is completely predictable and absolutely devoid of any meaning.

As the merriment begins we learn that Lord Dudley Rancour has summoned ill-assorted characters for a weekend getaway on his luxurious estate on an island in the middle of a lake. This is an important element with a “severe electronic storm rapidly approaching, making the bridge to the mainland impassable.”

The visitors are strangers to one another, but their intimate connections are unraveled once the murderer is revealed.

Following their order of introduction, the six visitors are a blithe ingénue, Hope Langdon; a family doctor, Dr. Grayburn; the host’s rakish nephew, Nigel Rancour; an imperious dowager, Lady Manley-Prowe; an elderly army officer, Colonel Gillweather; and an amateur sleuth, patterned after the determined Miss Marple, but here named Miss Tweed. They are joined by the staff, Lettie, the Cockney maid; Flint, the randy groundskeeper; and Clive, the devoted butler. There’s also the varsity letterman, Geoffrey, a competitive rower who swam to the island when his racing shell capsized.

There’s a lot of silliness in “Something’s Afoot” but it’s all made believable by the top-notch cast, an essential factor to make a spoof work.

The most delightful performance is by Joseph Medeiros as the penniless leech nephew. His dedication to the character is a joy to watch as he flits across the stage with unabashed glee. Will Ray as Geoffrey and Laura Hall as Hope are also wholly enjoyable. Ray at first appears to be too old to play a collegiate oarsman and fervent suitor, but then audience members recall actor Van Johnson — who was nearly always cast in roles too young for his age — and we are in on the joke. Ray and Hall are clearly enjoying their stage time and the joy of their romantic antics is infectious.

If only Angela Lansbury were available to play Miss Tweed. Whether it’s because the character is underwritten or a playful homage to the beloved detective trope couldn’t be summoned, but Tia Speros misfires. Her character is overly dowdy but should be plucky with flashes of genius, and the actress seems to have little faith in her material.

The score is a disappointment, most notably in the first act when the songs delay rather than propel the story. But the songs are more distinguished and inventive in the second act, especially the witty “The Legal Heir” and the raucous “Dinghy” with its nod to British music hall.

In short, “Something’s Afoot” is the funniest musical Agatha Christie never wrote, memorable for its spirited direction and proficient cast members.

Content advisory: minor sexual innuendo