The unusual aspect here is that all of the show’s music is vocalized by the cast, whether in solos or background music. There are no instruments, only the versatile voices of the actors. The book, music and lyrics are credited to Kristen Anderson-Lopez, James-Allen Ford, Russ Kaplan and Sara Wordsworth, based on an original concept created along with Gregory T. Christopher and Karla Lant.

We get the idea at the outset, thanks to the exuberant and often hilarious performance by Chesney Snow in the role of Boxman. (It is also performed on some nights by Steven “HeaveN” Cantor.) Boxman communicates in a variety of sounds that go with what he tells us. Snow seems to be able to imitate any sound one could imagine, all flowing swiftly in syncopation with his lines.

The 11-member cast also includes of David Abeles, Moya Angela, Justin Guarini, Telly Leung, Erin Mackey, Gerianne Pérez, Margo Seibert, James Snyder, Mariand Torres and Nicholas Ward.

The space is a rectangle in the Circle In the Square, a theater that usually presents staging problems, depending upon where one sits. At one length of the set (design by Donyale Werle) is a subway entrance, complete with ticket machines that don’t always work, a booth with a sharp-tongued attendant, and stairways leading down to the platforms. Where the tracks would be, there is a movable stream of seats and (think imaginatively) office desks that shuttle back and forth within the rectangular space. I sat at the far end from the subway entrance, which provided a clear overview.

But the broader playing area made it take more time for me to get to know the individual characters closely than it did in the more intimate off-Broadway milieu. But eventually the bond was struck with characters that include two gay men wanting to marry but with one having problems breaking the news to his very religious mother; an aspiring actress who keeps being rejected; a subway rider who repeatedly has trouble with the attendant, and characters searching for romance.

The direction and choreography by Kathleen Marshall makes the company come across with sparkle. The musical direction is by Rick Hip-Flores, and the a cappella arrangements are by Deke Sharon.

The songs reflecting the problems of the characters include “Not There Yet," “Broke,” “Saturday Night Obsession,” “A Little Friendly Advice” and “Getting There,” along with other defining numbers. The solos are generally striking, and when the company breaks loose in song as a unit, such as in the finale, the effect is electric.