You know you’re in for a good time when there’s a straw-thatched margarita bar set up in The Gateway’s front courtyard, with nautical rope looping up the railing and vintage boat magazine ads tucked along the side. Then the actors come out and sing songs like “Bring Me Two Pina Coladas” and “Brown-Eyed Girl.” Patrons wearing shorts and flowered shirts jump into the spirit and dance along with the performers, as the cast leads the way inside the theater down the aisles and onstage.

Suspend your imagination. It’s like the best party you ever went to, and that’s what The Gateway’s “Escape to Margaritaville” offers, a hilarious party with sing-along Jimmy Buffett songs, wrapped around a feel-good story and a passionate cast, that debuted Friday night.

So here’s the premise.

Two best friends from Cincinnati decide to take a weeklong vacation to a Caribbean spot that has a volcano. Rachel (Sarah Ellis) is an environmental scientist, serious about her work. Tammy (Katelyn Lauria) is a sweet girl about to marry a condescending jerk who wants her to lose weight.

Upon arrival, the friends realize the Margaritaville Hotel is not the lux place they anticipated, but the staffers lighten up their disappointment. There’s guitar-playing entertainer, hunky Tully (Cody Craven), who has his eye on Rachel but is afraid of commitment, and bartender Brick (Hunter Brown), who makes a beeline for Tammy. Soon, the women catch the “don’t worry, be happy” atmosphere.

And so does the audience.

Hunter Brown is brilliant as the goofy but kind Brick. He steals the show, as does Katelyn Lauria’s Tammy. Brick is as pun-loving and sweet as Tammy. The kick line he does on the top of the mountain with a volcano about to blow, joined by a chorus of dead insurance agent zombies who died in the last lava flow (a recurring fear he has), is over the top. When his anxiety starts to dissipate, they begin to disappear. But then, he starts missing them.  “Wait! We can order some Outback Steakhouse!” he calls out.

(You can’t make this up! But someone clearly did.)

Catch this duo in “Cheeseburger in Paradise.” It’s what Tammy wants to eat at her subsequent rehearsal dinner; she’s tired of dieting, but her fiancé tries to stop her.

He doesn’t want a fat wife. Oooh! Wrong move, dude!

We’ll stop here, but the “Cheeseburger in Paradise” number is an over-the-top, boisterous hoot.

Gateway artistic director Paul Allan provided a little insight into the main characters. Sarah Ellis (Rachel), who has a wonderful voice, was the lead in “The Wedding Singer.”

“We had Sarah picked for this role. [Director/choreographer] Keith Andrews had done this musical in Northport and I liked his cast, but I immediately thought of Sarah,” he said.

Cody Craven as Tully plays the amorous but likeable singer, a philosopher with a surprising vulnerable side, and you wind up rooting for him.

“We had to find the right person,” Allan explained. “His character is heavy on guitar playing. So he had to be very charismatic, good looking, sing, play the guitar and act, and all that’s hard to find. He comes from California and auditioned via video tape.”

The whole cast and orchestra rocks it, with some you’ll recognize from other Gateway shows, but we have to mention Broadway veteran Bill Carmichael as J.D., the one-eyed beach bum (looking for his lost treasure) with a surprisingly tender heart who delivers almost spiritual  observations when not drinking; and Ebony Marshall-Oliver, another Broadway and Off-Broadway actor, as Marley, the sassy, funny owner of the hotel. They play mature characters in a will-they, won’t-they tug of war.

There’s a gratifying message plunked into the riotous zaniness. And that is, realize your dreams, but don’t forget about love and having fun. That was Jimmy Buffett’s mantra. While he sadly died last year, Buffett was well-liked, generous, and his laid-back, tropical rock sound resonated with a generation (think Parrot Heads). He inspired enjoying life and following your passion, and his success lassoed over 30 albums—several gold and platinum—several restaurants and other businesses. His music even made it to Broadway.

There are 24 songs, including “License to Chill,” “Margaritaville,” and  “Why Don’t We Get Drunk” (think of your college days with that one.)

The finale is uproarious.

Don’t forget to dodge those beach balls!

It’s playing to July 21. Get tickets at www.thegateway.org.