Mark Jaster, Alex Vernon, Sarah Olmsted Thomas, Sabrina Mandell and Gwen Grastorf in Happenstance Theater’s homage to vaudeville, “Moxie: A Happenstance Vaudeville” at Round House Theatre. (Cheyenne Michaels)

To enthusiasts of the musical saw: The long dearth of performances is over. The instrument sings out multiple times in Happenstance Theater’s diverting and sneakily resonant “Moxie: A Happenstance Vaudeville” at Round House Theatre.

A tongue-in-cheek homage to vaudeville, entertainment that was an American staple from the late 19th century through about 1930, “Moxie” features, as one of its endearingly hapless performer characters, a musician who plays the saw. In the hands of this virtuoso, the sound of the tool-turned-concert-novelty is both comical and poignant, like “Moxie” itself. (“Moxie” follows another Happenstance valentine to a historic showbiz mode: 2015’s “Impossible! A Happenstance Circus,” winner of several Helen Hayes awards.)

Vaudeville reveled in variety, grouping performers from diverse backgrounds and disciplines. So the 90-minute “Moxie” slots its musical-saw player onto a bill that also features, among other highlights, a ventriloquist, a flamboyantly incompetent magician, a yodeler, a Loie Fuller-like dancer, many comedians and an egoistic dramatic actress who declaims Shakespeare in a plummy British accent.

All of these figures are channeled by members of the Happenstance ensemble: Mark Jaster, Sabrina Mandell, Karen Hansen, Gwen Grastorf, Sarah Olmsted Thomas and Alex Vernon. Han­sen usually sits at a piano on one side of the footlight-bedecked stage, where she plays accompaniment for vintage songs such as “Shine On, Harvest Moon.” (The show steers clear of the ethnic-caricature and blackface acts that were popular vaudeville genres but are repugnant today.)

With its stream of motley diversions, “Moxie” has the piquant flavor and pacing that surely contributed to vaudeville’s appeal. At the same time, this show maintains a sly modern perspective, drawing attention to the old-fashioned nature of many of its acts. The Shakespearean actress deploys grand stagey gestures. A series of droll narrative tableaux goes to town on melodrama. And the jokes served up in the comedy turns are gleefully un-edgy. (What do cats like to eat in the summer? Mice cream!)

Alex Vernon and Sarah Olmsted Thomas as Pierrot-like figures in “Moxie” at Round House Theatre. (Cheyenne Michaels)

But the deft archness subsides in a lyrical stilts-walking act featuring two Pierrot-like figures silhouetted against a night sky. (Mandell designed the atmospheric costumes.) The wistful mood of the sequence — one of the Pierrots covets the moon — finds an echo in the sections of “Moxie” that allude to passing time. For instance, in an encore turn, the Shakespearean actress loses the thread of her monologue and begins to reminisce about her career. The musical-saw virtuoso ages over the course of his appearances, moving ever more gingerly.

Other points in the show — a pensive filmed sequence and a tribute to old-time radio — refer to media developments that contributed to vaudeville’s demise. Funny and entertaining as “Moxie” is — did we mention the comedian in a bear suit? The meatball-juggling scene? — it artfully encompasses a nod to mortality.

Moxie: A Happenstance Vaudeville, collaboratively devised by Happenstance Theater. Music arranged and/or composed by Karen Hansen; lighting design, Kris Thompson; set design/construction, Alex Vernon and Mark Jaster. 90 minutes. Tickets: $26. Through July 17 at Round House Theatre, 4545 East-West Hwy., Bethesda. Call 240-644-1100 or visit roundhousetheatre.