Defying us delightfully to make sense of it, 'Shear Madness' opens the 2017 season at Beef & Boards Dinner Theatre

Mikey (in barber chair) and Nick (standing next to it) interrogate suspects Tony (from left), Barbara, Eleanor, and Eddie.

My perverse response to "Shear Madness," the popular whodunit that opened Beef & Boards Dinner Theatre's 2017 season Friday night, is that I was left with more questions about the murder victim than about the four suspects' talk and behavior.

Isabel Czerny, a concert pianist who apparently was seeking to revive her career,  lived upstairs from a hairstyling salon on Massachusetts Avenue. (The setting and dialogue of Paul Portner's long-running show are conventionally altered to localize each production.)

Typical of the genre, one character is more blatantly put forward as a suspect than the others, but is usually not the perpetrator. I can't tell you if this convention was followed or violated on opening night, because the gimmick of "Shear Madness" is that the audience is brought into the investigation and votes at each performance for its "whodunit" candidate. The cast then plays out one of four endings, depending on audience choice.

The one character who stands out when it comes to motive is Tony Whitcomb, the flamboyantly gay proprietor of the salon. He hates Isabel's continual practicing, focusing on her beloved Rachmaninoff. He seems desperate to get her to desist by any means necessary.

My first question is why a piano upstairs is so disturbing when Tony has programmed old pop hits during business hours. We assume this is constant and loud; for the sake of hearing dialogue, however, the soundtrack is cut off for most of the action. But Daniel Klingler, as the fiercely buoyant, outsize, easily distracted Tony,  grooves to the beat comically in the opening scene before the dialogue takes over. Tony's recorded preferences would seem to have no trouble dominating the salon's atmosphere.

Salon boss Tony Whitcomb and his assistant show off their new aprons.

It's also irritating to him that she plays bits of pieces, working some passages over and over, but not the whole piece. So I wondered why someone trying to revamp a professional career would never do a play-through. In practice, pianists woodshed difficult passages, or those that pose interpretive problems, but that's not all they do.

Then there's the question of the cassette player that the murderer turns on after the deadly deed to make it seem as if Isabel is still at the keyboard. A cassette player, as everyone will remember, has questionable fidelity, especially at loud volume. How could its Rachmaninoff not sound different from "live" playing at a concert grand, even heard through the ceiling?

Isabel's long-ago breakdown, as described by Tony, seems wildly improbable: a kind of hysterical paralysis in mid-performance, both hands having floated upward and gotten stuck high above her head. True, the comic-whodunit genre doesn't owe much to realism, but this description makes it hard to believe that Isabel is anything more than a wraith to hang a plot on.

As to her character, it's not clear to me whether Isabel was passive-aggressive, oblivious to the discomfort she was causing her neighbor, simply obsessed with resuming her career and thinking of nothing but her music, or cruelly manipulative. (The last possibility moved front and center according to the conclusion played Friday.)

I must give up on Isabel, after two more observations:  I have a sense, based on some Rachmaninoff browsing at home, that she was working on the first movement of the Rachmaninoff's Sonata No. 2 in B-flat minor, op. 36.  The movement is headed  "Allegro agitato," and a mood of agitation is essential to the play.

Overcome by the bloody scene upstairs, Barbara faints.

Moreover, she shares a surname with a famous pianist-composer of history, Carl Czerny, who has been described as "a man of sour disposition who disliked children and therefore did nothing but write etudes." Tweaked a bit, the description applies to Isabel, whose etude-like focus bothers Tony as much as Carl's useful etudes have annoyed generations of burgeoning pianists.

The cast is marvelous at keeping the pot boiling. Directed by Eddie Curry, they pop into and out of the salon, which is splendidly designed and lit by Michael Layton and Ryan Koharchik, respectively. Much of the cast's business and dialogue is puzzling, fragmentary,  and intended to distribute red herrings liberally. All of it generates plenty of questions that Jeff Stockberger, as police lieutenant Nick O'Brien, commandeers from the stage and gathers during intermission, when I overheard several pointed observations directed at him. In the second act, when O'Brien further questions the four suspects (with the audience's help), they present more fishy explanations than a Kellyanne Conway news conference.

Nathan Robbins is Mikey, O'Brien's boyish, wide-eyed sidekick. Jenny Reber plays the flighty and flirtatious Barbara DeMarco, Tony's assistant. Antiques dealer Eddie Lawrence (Michael Shelton) is surreptitiously involved with her, and his customer status is somewhat dubious. Eleanor Shubert (Suzanne Stark) is a highbrow Carmel socialite, a regular who deigns to venture below 96th Street to get her hair done, placing her on this occasion uncomfortably in the middle of a homicide investigation.

I may have made "Shear Madness" seem more complicated than it's supposed to be. As the malapropism-prone Barbara says: "It's not rocket surgery." But delightful as getting all tangled up in the play is, it tends to spur questions so profusely that you become doubtful of what you've seen and what you've been told — and how to process it all.

To quote Barbara again: "I think I have ambrosia." Perhaps that will become a common complaint in today's post-truth environment.