Bradley Greenwald is a baritone who plays the baritone horn and he comes at us with both baris in “The Longest Night: A Solstice Cabaret.”

A couple of theatrical flourishes enliven the performance at Open Eye Figure Theatre in Minneapolis: a snowstorm and a long blackout that offers audiences a disorienting preview of Dec. 21, the nightiest night of the year.

But “The Longest Night” is more concert than play, with creator/performer Green­wald blending poetry and songs, nimbly accompanied by Sonja Thompson on piano. It’s a sweet, cozy performance that celebrates the solstice in a way that feels richer for its acknowledgment that darkness and chill do bring with them some melancholy.

That theme is best expressed by Leonard Cohen’s “Anthem” and its message that “there is a crack in everything/that’s how the light gets in.” There is a lot of light in “The Longest Night,” both literally (who doesn’t love a candle?) and metaphorically.

Edvard Grieg’s song “The Shepherd Boy” seems to summon the feel of a slow trudge through piles of snow as well as the sun, breaking through the clouds.

The Dar Williams tune “The Christians and the Pagans” is a charmer about how the title characters forget their differences when they sit down for a Christmas Eve dinner at which they escape the cold together and find “faith and common ground the best that they [are] able.”

Finding common ground is a key element of “The Longest Night,” which pays a little attention to the various holidays people celebrate this time of year but much more to the dark and cold we all share, regardless of our beliefs.

“I have faith in night,” says the affable Greenwald, who probably knows a thing or two about how difficult it can be to keep up one’s energy, since he’s currently in both this show and Sewell Ballet’s “Nutcracker (Not So) Suite.”

Greenwald gets laughs with a take on Carole King’s “So Far Away” that is sung to the sun, and lures us all into the solar celebration with a singalong to “Let the Sunshine In,” which felt surprisingly good, even to this extremely limited singer.

As the show progresses, “The Longest Night” begins to look forward to the new year and Greenwald notes that, yes, we’re about to have the year’s darkest blast of darkness but that the days begin getting longer immediately after that.

“We yearn for a clean slate,” he says, offering a homespun ritual that attendees can perform on the way out of the theater to say goodbye to any mistakes they’ve made in the past year and look forward to trying to get them right in the next.

It’s a warmhearted conclusion to a show that feels like both a public service and a darn good time.