Book, music, and lyrics by Irene Sankoff and David Hein. Directed by Christopher Ashley. Until Jan. 8 at the Royal Alexandra Theatre, 260 King St. W. Mirvish.com, 416-872-1212 or 1-800-461-3333.

On Sept. 11, 2001, a group of Canadians humbly stepped forward to do their part in the aftermath of terrorist attacks on New York and Washington D.C. that appalled the world.

Come From Away, a big-hearted, thoroughly enjoyable new musical by Irene Sankoff and David Hein, celebrates the generosity of the people of Gander, Newfoundland, and its neighbouring towns in welcoming more than 6,500 passengers from jets grounded there when the United States shut down its airspace.

This might sound like unlikely material for its chosen medium – a 9/11 musical, really? – but Sankoff and Hein make it work by focusing not on the horrifying larger context but by offering up a story that demonstrates the power of community and an almost overwhelming belief in the possibility of kindness. A talented and versatile cast of 12 all play multiple roles and, crucially, switch between identities as locals and “plane people,” underlining the message of shared humanity.

Come From Away really really believes in goodness and it really really wants you to believe in it too. In this, it is far from subtle. But appreciation of it is greatly enhanced by the knowledge that the musical’s storylines are based in truth. Sankoff and Hein did deep research in Gander, interviewing everyone from police officers (one is played in the show by Geno Carr) to the town’s only TV reporter (Kendra Kassebaum), as well as a number of those who were grounded there.

The aesthetic is rough-hewn simplicity, underlain by sophisticated, tightly executed craftsmanship. Christopher Ashley’s production has a driving pace that grabs the audience’s attention and barely lets go throughout the one-act, 110-minute running time.

An emphasis on plain-spokenness is underlined in the approach to performance: The cast sing and speak as much out to the audience as to one another.

The first number, ” Welcome to the Rock,” firmly roots the show in its Newfoundland location (“Here on the edge of the Atlantic, on an island in between there and here. . .”), while also establishing Sankoff and Hein’s approach to songwriting, which mixes classic musical theatre elements with folk and rock elements.

Ian Eisendrath’s cracking eight-person band features Celtic instruments (pennywhistle, fiddle, bodhran drum), which come to the fore in a cathartic scene of a riotous party at the local Legion Hall.

An ongoing theme is extreme rural isolation, suggested by Beowulf Boritt’s gorgeous set: a back wall covered in horizontal wood panels, and a bare stage lined with trees. Eisendrath’s band is just about visible in the grove. Howell Binkley’s masterful lighting has the capacity to quickly shift mood and tone, as when back-lighting reveals that seemingly solid wall actually to be slatted, so that beams can shine through.

The centre of the stage revolves, which Ashley uses with great effect to complement the fast-moving storytelling and shifts of location. Sitting in rows on simple wooden chairs, the cast are airline passengers. Then, moving the chairs around as the stage spins, they become a room of tense air traffic controllers. Then they transform into Gander’s town council in an emergency planning meeting for the impending arrivals.

The show is full of engaging, surprising and often funny details as we are invited to look at the complexities of the influx of “come from aways” (local slang for outsiders) from multiple perspectives. Wisely, Sankoff and Hein choose one planeload, piloted by Beverley Bass (Jenn Colella), as the focus of their storytelling. We meet them at the midair moment when they’re re-routed.

Notable characters on that flight are a gay couple (Chad Kimball and Caesar Samayoa), whose relationship troubles could have used more fleshing out; and a middle-aged Texan woman and Englishman (Lee MacDougall and Sharon Wheatley) who catch each other’s eye.

On the ground, we meet Gander Mayor Claude Elliott (Joel Hatch), first exhorting the local population to rise to the challenge of the new arrivals and then coping with generosity that won’t stop – this includes chilling a surplus of donated food on the local ice rink.

In several short monologues delivered with brilliant comic timing, New Yorker Bob (Rodney Hicks) reacts incredulously to the lack of crime in the area. He can’t figure out where to hide his wallet, and slowly realizes there is no need to.

Another running subplot is the doughty efforts of local SPCA employee Bonnie Harris (Petrina Bromley, the cast’s only real-life Newfoundlander) to care for the many animals stranded in planes’ holds, including a pregnant Bonobo ape.

The most direct connection to what’s happening in New York is the agonized wait of Hannah (Q. Smith) for news of her firefighter son. Her scenes of conversational bonding with local woman Beulah Cooper (Astrid van Wieren) provide welcome quiet moments in what sometimes feels like a relentless tide of high energy.

Also cutting through the portrayal of idyllic togetherness is a subplot about the suspicious treatment of an Egyptian Muslim passenger (also played by Samayoa), plus several scenes in which tempers and nerves flare as the visitors feel increasingly starved for news and impatient to get home.

Ingenious casting and costuming (by Toni-Leslie James) underlines the overall message of the extraordinary in the ordinary. These actors look like real people – different shapes and sizes, not all model-gorgeous – but they have superb singing voices, facilities for accents, and capacities to change between characters via vocal, physical and energetic shifts with lightning quickness. Who and where they are never becomes muddy (though problems with shorting-out body mics on opening night made for a rough few minutes of audibility).

Many narrative strokes are broad, and some references may feel predictable to Canadian audiences (yup, there’s an ongoing Tim Hortons gag). But we are not this show’s primary audience: seeded by the Canadian Musical Theatre Project at Sheridan College, it was developed in several American workshop programs, road-tested at three U.S. theatres (in La Jolla, Seattle, and Washington D.C.), and is headed to Broadway in February.

While there is some cause for worry that this show’s emphasis on good ol’ Canadian goodness could be eaten alive by New York cynicism, recent events may have played in its favour. On Nov. 8, 2016, the world changed again with the election of Donald Trump, an event many are likening to 9/11 in its ground-shaking effect on the American (and global) consciousness.

As the real-life Mayor Claude Elliott told the ecstatic opening night audience in a curtain speech, “The world we live in today needs a good story.” Reminding our American cousins what civility looks and sounds like might actually strike a welcome chord.

In the meantime, GTA audiences have more than a month to make up their own minds about Come from Away, and can do so in the spiffy environs of the newly renovated Royal Alexandra Theatre, super-comfy new seating and all.

There’s a whole lot to be proud of in this show.