The cast of “Company” serenades Bobby (Matthew Scott; center) as they sing “Side By Side By Side.” The show plays at Virginia’s Signature Theatre through June 30, 2013. (Scott Suchman/Scott Suchman)

The laughs are as big as the perplexities of personality are deep in Signature Theatre’s creditable, vocally adept version of Stephen Sondheim and George Furth’s oft-revived “Company.”

Two performances take special advantage of the comic possibilities of their characters, in ways not always as ripe in stagings of this 1970 musical, concerning the curious case of Bobby, handsome bachelor and chronic commitment-phobe. With a few clarifications in its concept, this “Company” could frame these and the other performances in an even more sharply compelling manner.

It’s Erin Weaver as Amy, the neurotic bride-to-be melting down on her wedding day, who offers up one of these socko turns. You may remember her as the goddess gliding cheekily on roller skates last summer in Signature’s clever “Xanadu.” Now, her feet planted firmly on the stage, she provides a smart new spin on Amy and, in the process, delivers a version of the dazzling tongue-twister number, “Getting Married Today,” that is guaranteed to give show-tune fanatics chills.

The other knockout comes from the divine Madeline Botteri, cast as April, the sweet flight attendant Bobby beds who’s hilariously cognizant of her intellectual limitations. Giving her speeches a Midwestern singsong, Botteri finds in her April an implausibly lovable blankness, akin to the soft-spoken cluelessness of Georgia Engel’s Georgette on “The Mary Tyler Moore Show.”

Several other actors prove to be deft conservationists in director Eric Schaeffer’s production, wasting not a moment of stage time. These include Tracy Lynn Olivera, as the biting distaff half of a couple too competitive for their own good, and Bobby Smith, who proves that the story of a dissolved marriage in which the partners stay together doesn’t have to seem totally insane.

“Company,” Stephen Sondheim’s new musical comedy about a 35-year-old, commitment-phobic New Yorker named Bobby who is struggling to settle down. Directed by Eric Shaeffer, the musical will run at Signature Theatre until June 30. (Signature Theatre/The Washington Post)

And as Bobby himself, Matthew Scott has the winning double-barreled combo of looks and voice that compel you to ponder anew the age-old conundrum about “Company”: Who the heck is this Bobby, and why in this tale of missed chances for a single man are the only guests at his 35th birthday party five married couples?

Schaeffer’s smooth and strongly sung production is a bit fuzzy on this question, and while the approach here does no real harm to the show, it doesn’t advance our understanding of it much, either. One key facet that could use some refinement is when, exactly this “Company” occurs. This is no small issue in a musical attempting to take the social temperature of a time and place, by one of the most urbane composer-lyricists in history.

The Bobby who existed in 1970 is a different sort of 35-year-old than the one in 2013, just as the definition of marriage has evolved in the 43 years since “Company” opened. (“Company,” written today, surely would include at least one gay marriage.) The references in Sondheim and Furth’s “Company” are to New York in the late-middle 20th century: In the famous 11 o’clock number “The Ladies Who Lunch,” Joanne — played as a shrill cocktail-lounge loudmouth by Sherri L. Edelen — sings of women who are “clutching a copy of Life / Just to keep in touch.” Life magazine hasn’t occupied a prominent spot on the American scene for decades.

How that jibes in Daniel Conway’s mostly abstract set design with New York apartments full of kitchen appliances out of a Sonoma Williams catalogue isn’t clear. And the references to Prozac, busy signals, answering machines and vintage Volkswagens leads one to the conclusion that we’re in some time-free zone. In an examination of the mores and institutions that help define a culture, this leaves us with conceptual squishiness.

You can sympathize with Schaeffer’s predicament, as he used a script that includes a scene added to a London production of “Company” that attempted to answer a question that has long been debated by Sondheim enthusiasts: Is Bobby gay?

The new scene, on the balcony of the apartment of Susan and Peter — the couple who live in divorced bliss — has Peter propositioning Bobby directly. Scott’s Bobby seems to be genuinely taken aback as he explains he’s not interested. The problem isn’t that the scene seems to take gayness off the table; it’s that it’s poorly written.

In other instances, though, Schaeffer skillfully mutes the effect of silly situations that might come across like episodes of “Love, American Style.” Maybe it’s because three of the five couples in Signature’s “Company” are married in real life that some of the scenes communicate an appealing intimacy.

Choreographer Matthew Gardiner brings this quality of coziness into the couples’ dance numbers, which manage to evoke ease and warmth. Frank Labovitz’s costumes, all neutral grays and whites, contribute to a sense of these friends as a unit — although the issue of what decade we’re in crops up again in the odd outfit Labovitz’s come up with for Carolyn Cole’s Marta, the kookiest of Bobby’s dates.

Cole’s big-belt rendition of “Another Hundred People” is, like most of the numbers, excellent. Backed by conductor Jon Kalbfleisch’s nine-piece orchestra, Scott’s “Being Alive” provides another satisfying high. And the version of “You Could Drive a Person Crazy” performed by Botteri, Cole and Jamie Eacker is packed with sass.

It’s Weaver who takes “Company” most successfully in a novel direction. Amy is usually played as fragile and sort of ditsy, a woman panicking at the final leap into full-fledged adulthood. (As her patient groom, Paul Scanlan proves an ideal foil.) But Weaver manages to convince us that “Getting Married Today” is a kind of manifesto of clear-headedness. Her reasons for not getting married — she does get hitched, of course — make far more sense than anything Bobby can come up with.

Company

music and lyrics by Stephen Sondheim, book by George Furth. Directed by Eric Schaeffer. Choreography, Matthew Gardiner; music direction, Jon Kalbfleisch; set, Daniel Conway; costumes, Frank Labovitz; lighting, Chris Lee; sound, Matt Rowe; associate video design, Rocco DiSanti. With Carolyn Cole, Jamie Eacker, Sandy Bainum, Thomas Adrian Simpson, Evan Casey, Erin Driscoll, James Gardiner. About 2 hours 40 minutes. Through June 30 at Signature Theatre, 4200 Campbell Ave., Arlington. Call 703-573-7328 or visit www.signature-theatre.org.