“A Funny Thing Happened on the Way to the Forum” does not include meaningful political subtext or deep social commentary, so it has survived for more than 50 years in American theaters purely through its comical hi-jinks and catchy light tunes. In other words, if the show is not “funny,” it doesn’t have much else going for it.

Echoing tones of Shakespearean comedies — with gender-bending mistaken identities, star-crossed lovers and characters rushing around the stage in mass chaos — this musical begins by breaking down the fourth wall of the theater, with actors foreshadowing to the audience what silliness they will soon see. Then the actors go about delivering those predictable plot points, with few surprises, including an anticlimactic ending that should register shock (but in this incarnation doesn’t).

The Manoa Valley Theatre version of “Forum,” continuing through April 3, struggles with many aspects of this well-worn work and fails to elevate the singing, dancing and farcical actions beyond the broadest of appeals. The cast often tries too hard for laughs and, in many cases, squeezes the funniness out of the jokes. Without great singing voices or dance choreography to compensate, the production plods through more than 2-1/2 hours of the lightest traceable forms of humor.

This is an effort filled with good intentions, such as the inclusion of a five-piece band. Yet the musicians and conductor are placed behind the set, out of view, and their instruments get muffled in ways that muddy the sound and call into question the choice of live music over a digital recording.

The lead character, Pseudolus, played by Reyn Halford, is based on a similar character in the work of Roman playwright Plautus from about 200 B.C. “Forum” was inspired by the Roman’s writings, especially his farces, and is intended to illustrate the ludicrous nature of people in love across time immemorial. Written by Burt Shevelove and Larry Gelbart, the musical originally foundered until a young composer named Stephen Sondheim added the brilliant tune “Comedy Tonight” to the opening.

The impact of that one song on the fate of “Forum” demonstrates how much music, singing and dancing can mean to a key moment of a piece, especially in this humor genre. Manoa Valley Theatre’s production not only offers subpar versions of “Comedy Tonight” and other foundational musical numbers, it also presents little else to distract from those deficiencies.

Halford, as the narrator and protagonist, is a gifted physical performer, handsome and athletic. He performs front flips and backflips, high-leg kicks and splits, and generally remains focused and engaged in his role at the center of the action. His high physicality often overshadows the less agile performers nearby, and his singing voice clearly was not his strong point on opening night, when various technical glitches turned microphones on and off at inopportune moments and generally caused an uneven soundscape.

Some of the performers had sections of songs that they sang quite well (Kati Kuroda as Domina and Victoria Brown-Wilson as Philia come to mind), yet even the best of the musical performances in this show were spotty. This might have been an issue with not warming up properly or the sound system inconsistencies, since the voices seemed to gradually improve, but it also could have been the case of the show’s producers making difficult choices about the complexities of the talent, as in Halford’s potential for gymnastics outweighing his limits in his vocal range.

Anachronistic curiosities, meanwhile, included characters in Chuck Taylor high tops, a modern coffee table used as a makeshift funeral slab and a walking staff with a rubber tip. Some of the set’s doorways were too small, as was noticeable when a Roman captain tried to walk through them with a helmet on, and the costumes of the courtesans looked more like they were from the 1980s than ancient Rome.

The show is supposed to be funny, but not in that way.

The occasional jolt of genuine humor was provided by Allan Y. Okubo as Erronious, as he wandered around the Seven Hills of Rome; Viviann Kapua‘ala as the catlike Vibrata; and Protean chorus member Christine Lamborn as she shifted in and out of her role as a eunuch. They were laugh-out-loud funny at times.

That these minor characters made the biggest impression is an indication that this fluffy piece at Manoa Valley Theatre has even more air in it than it should.

‘A FUNNY THING HAPPENED ON THE WAY TO THE FORUM’

>> Where: Manoa Valley Theatre, 2833 E. Manoa Road

>> When: 7:30 p.m. Wednesdays and Thursdays, 8 p.m. Fridays and Saturdays, and 4 p.m. Sundays, through April 3

>> Cost: $39 ($34 for senior citizens/military, $20 ages 25 and younger)

>> Info: manoavalleytheatre.com, 988-6131

The play:

>> Directed by Hannah Schauer Galli, with assistance by Laura Clark Greaver; set design by Andrew Doan; lighting design by Janine Myers; costume design by Jennifer Hart; hair and makeup design by Lisa Ponce de Leon; technical direction by Newton Koshi; sound design by Jeff Weinkauf; props design by Sara Ward; musical direction by Phillip Ikaika Foster; choreography by Erin McFadden; and associate producing by Bree Kale‘a Peters

The players:

>> Reyn Halford (Prologus/Pseudolus); Stephen M. Foster (Senex); Kati Kuroda (Domina); Alika Bright (Hero); Neil Scheibelhut (Hysterium); Allan Y. Okubo (Erronius); Kenny Kusaka (Miles Gloriosus); Montana West Rizzuto (Lycus); Christine Lamborn, Ryan Okinaka and Collin Wong (The Proteans); Christina Torres (Tintinabula); Katja Berthold (Panacea); Charlene Elva Pratt and Tania Wilk (The Geminae); Viviann Kapua‘ala (Vibrata); Anette Aga (Gymnasia); Victoria Brown-Wilson (Philia); and musicians Pavlina Nakalenova, Sean Choo, Derek Higashi and Jazzton Lyons