Subways are for singing, at least in the world of “In Transit,” the charming a cappella musical of metropolitan life that’s rapturously harmonious, even when the times aren’t. The likable, lightweight tuner, which had a run in 2010 at 59E59 — and an even earlier version as “Along the Way” at 2003’s New York Fringe Festival — evokes musicals and revues that celebrate the buzz of being young, hopeful and ever-striving in New York. Okay, so the storylines go back to the days when you still used tokens. But what gives “In Transit” its new swipe is what’s not there — the orchestra — and what is — glorious, pitch-perfect voices, set to Deke Sharon’s rich and expressive arrangements.

It’s all backed by the percussive, beat-box talents of Chesney Snow, who plays a zen-like subway performer named Boxman (Steven “HeaveN” Cantor in alternate performances). Boxman is the show’s underground guide to the musical’s other characters, who are stuck in life while on the move, and who often find themselves “in this limbo life between stations.” Donyale Werle’s witty subway platform of a set is an ideal fit for the Circle in the Square configuration, with the audience sitting on either side of its “tracks.” Donald Holder’s lighting and Ken Travis’ sound designs also add to the subterranean ambiance. Director Kathleen Marshall, who also choreographs, keeps things fluid, energetic and precise.

A quartet of writers, who were in an a cappella group years ago, wrote the book and penned the music and lyrics — after a concept credited to the quartet, plus two others. Despite the crowd, no one is breaking any new ground here, beyond the a cappella idea.

Moving among the predictable, interwoven story lines are Jane (Margo Seibert), an aspiring actress/temp on the verge of calling it quits on her dreams; Nate (James Snyder), a down-on-his-heels Wall Street guy who is discovering humility the hard way; his sister Ali (Erin Mackey), a young woman new to the city who is still obsessed with the guy who dumped her; and Jane’s agent Trent (Justin Guarini), who is unable to tell his fundamentalist Texan mother (Moya Angela) about his relationship with his “roommate” Steven (Telly Leung).

Although updated with references to misguided e-mails, regrettable texts, gay marriage and the challenges of the Metrocard, the book is by-the-numbers, with the audience’s minds moving ahead of the plot faster than a scurrying subway rodent.

All the performers bring a high degree of likability to otherwise plaintive roles: Seibert is just vulnerable enough as a woman at a crossroads; a disarming Snyder makes one actually feel for his humbling plight — and who can’t identify with his turnstile traumas?; Guarini and Leung are adorable (even if their marital resolution is unearned, but at least Guarini gets a lovely ballad out of it, “Choosing Not to Know”) and Mackay gives neuroses a funny spin.

Angela scores big in three roles: as a mother in denial, as a seen-it-all transit booth worker and especially as an office manager who lets loose with a “give-up” gospel number (“A Little Friendly Advice”). Another stand-out is Nicholas Ward’s basso profundo in the lively “Wingman.” He pretty much lays the ground floor of the score, which overall is consistently tuneful and smart, especially Jane and Nate’s duet of modern non-commitment, “But, Ya Know,” and Jane’s happy anthem of perseverance, “Do What I Do.”

The players are all multi-taskers, not only providing bright, polished performances but all having a continual vocal presence, playing exquisite back-up to each other’s numbers. It’s a surprisingly moving experience that make you feel that though you’re watching separate lives of these strangers on a train, you’re hearing the heart of one connected urban village.

Broadway Review: A Cappella Musical ‘In Transit’

Circle in the Square; 685 seats; $159 top. Opened Dec. 11, 2016, reviewed Dec. 9. Running time <strong>ONE HOUR 40 MINS.</strong>

  • Production: A Janet B. Rosen, Marvin S. Rosen, Robert F. Smith, Jeff Hecktman, Ed Rendell/Kenneth Jarin, Manny Medina, Frankel/Viertel/Baruch/Routh Group, Hello Entertainment/David Garfinkle, Michael S. Falk/Annie Falk, Karen Mehiel, Robert Sher/Sharon Azrieli, Mark B. Davis/Yoly Davis, Edgar Bronfman Jr./Benjamin Bronfman, Deke Sharon and Sleep Tite Productions presentation of a musical in one act with book, music and lyrics by Kristen Anderson-Lopez, James- Allen Ford, Russ Kaplan and Sara Wordsworth, based on an original concept by Anderson-Lopez, Ford, Kaplan, Wordsworth, Gregory T. Christopher and Karla Lant.
  • Crew: Directed and choreographed by Kathleen Marshall; set, Donyale Werle; costumes, Clint Ramos; lighting, Donald Holder; sound, Ken Travis; projections, Caite Hevner; music supervision, Rick Hip-Flores; a cappella arrangements, Deke Sharon; production stage manager, Kim Vernace.
  • Cast: Justin Guarini, Margo Siebert, Moya Angela, James Synder, Chesney Snow, Nicholas Ward, Telly Leung, Erin Mackey, David Abeles, Mariand Torres, Gerianne Perez.