Heeere’s Johnny (Josef Brown) and Baby (Amanda Leigh Cobb) in an earlier production. (National Theatre)

Musicals are different than real life. For example, in real life, communicating deep emotion by bursting into song is normally frowned upon. That rule is unexpectedly part of how things are done in “Dirty Dancing: The Classic Story on Stage” too.

“It’s not a musical,” says Conrad Helfrich, music supervisor for the show, which is making its American debut at the National Theatre on Tuesday. “It’s a play with music.”

The soundtrack — featuring songs like “Do You Love Me” and “(I’ve Had) The Time of My Life” — will be familiar to any girl who attended a sleepover from 1988 to 1992 or whose parents were lenient enough to let her see “Dirty Dancing” in the theater in 1987.

“[The music] is always part of the action, rather than a comment on the action,” Helfrich says. “A typical musical number is almost like a break. That doesn’t happen with us; there’s a story still going on.”

That story, about a rich girl named Baby and a bad-boy dance instructor named Johnny, takes place in 1963 at a resort in the Catskills. Instead of having Baby and Johnny serenade each other, the script leaves the singing to other cast members, who perform the songs while the action goes on around them.

“It’s a little like ‘Glee.’ I sort of hate to say that,” says Doug Carpenter, who sings many of the show’s songs. “Ultimately it’s really fun, and that’s part of what these songs are trying to do.”

A new character, Elizabeth, was created specifically for the stage show. “She pretty much ties the story together through song,” Jennlee Shallow says of her role. “She has a bunch of featured moments, mostly singing soul numbers.”

Carpenter isn’t sure what to expect when fans of the movie show up. One thing he’s certain of: When the show gets to “The Time of My Life,” the song that signals the final, triumphant dance sequence that releases Baby from her corner, “I imagine it’s going to go crazy,” he says. “You have all those memories of the movie and the nostalgia, and they give you that rush when you hear that song. I know I’ve had that thrill.”

National Theatre, 1321 Pennsylvania Ave. NW; Tue. through Sept. 14; $48-$98.

Don’t just sit there in the corner

To increase your enjoyment of “Dirty Dancing: The Classic Story on Stage,” become part of the show! Here are instructions on how to enjoy the production “Rocky Horror”-style. (Note: PLEASE DO NOT ACTUALLY DO ANY OF THESE THINGS.)

You will need:

— Maracas

— A watermelon

— Cooked spaghetti

— A baby doll

Moment: Dance instructor Penny shares the theological truth that “God wouldn’t have given you maracas if he didn’t want you to shake ’em.”

Action: Emphatically shake maracas.

Moment: Baby, in an attempt to make conversation with hunky Johnny, says, “I carried a watermelon.”

Action: Hoist watermelon above your head. Last person to put it down gets to cut to the front of the bathroom line at intermission.

Moment: Johnny admonishes Baby for having “spaghetti arms” and not maintaining her frame while dancing.

Action: Throw spaghetti at Johnny. Carbs are important to fuel the art of dance.

Moment: Johnny says THE LINE.

Action: Throw your baby doll into the nearest corner in defiance.

More stage stories:

The ‘Sunday in the Park With George’ scene team at Signature Theatre paints a (disposable) masterpiece of its own

Signature Theatre celebrates its 25 anniversary with — what else? — song

‘Good Times: A TV Theme Song Cabaret’ celebrates boob-tube tunes