Movies and TRAILER: Hugh Jackman and Zac Efron talk The Greatest Showman

The drum beat is pulsing, a fireball blows and a silhouette appears under the rafters in red tails and a top hat.

Suddenly your shoulders are moving in time to the music, a trapeze artist soars overhead, and Hugh Jackman's voice sings: "Ladies and gents, this is the moment you've waited for".

So begins The Greatest Showman - in a moment of pure exhilaration that sends a shot of adrenaline right into your veins.

The new movie musical, loosely based on the life of circus impresario PT Barnum and the origins of mass entertainment, draws you in before you've even caught your breath.

Jackman devoted years to bringing it to the screen and, in playing Barnum, embodies a creature of pure theatrical bravado.

"It's not exaggerating to say that Barnum ushered in modern-day America," he enthuses. "And especially the idea that your talent, your imagination and your ability to work hard should be the only things that determine your success.

"He knew how to make something out of nothing, how to turn lemons into lemonade. I've always loved that quality. He followed his own path, and turned any setback he had into a positive.

"So many things I aspire to in my life are embodied in this one character."

In fact Jackman is arguably a natural successor to Barnum. Perhaps our greatest living showman, he's a staple of both cinema and musical theatre.

His co-star Zac Efron, himself no stranger to musicals, certainly thinks so.

"Everyone wants to follow his lead," he gushes. "He sets the tone for everyone and we just try to live up to it, because it's pretty impressive."

The young star, who plays Barnum's fictional business partner, the disinherited socialite Phillip Carlyle, is positively animated as he adds: "He's the first one in and last one out at work. He's always in a good mood.

"He's learning as he goes, but he's always open-minded and willing and cool and fun to be around. He is the greatest showman."

But it wasn't always that way for Jackman, now 49, who admits that embracing his love of dancing was not always easy when growing up in Australia.

"I truly love dance," he says. "But there were eight years of my life that I didn't do it, just because I wanted to fit in.

"So now it resonates with me, and I think with most people on the planet, that to be authentically you is the only path that can bring you true happiness.

"Otherwise, you're putting on a mask to make other people happy. And as the father of two teenagers, I talk to them constantly about the idea that no matter who you are, no matter how you differ from supermodels and football players, it's irrelevant. Love yourself exactly the way you were born."

Embracing his inner showman has come a little easier for Efron, who was catapulted to global fame at just 18 as Troy Bolton in the High School Musical films.

Other actors might have run a mile from every other musical for the rest of their careers, but Efron didn't even pause when the part came his way.

"I had no hesitation whatsoever," he stresses. "I have always wanted to be back in the musical genre, but I never knew how it would happen.

"I thought it would be on Broadway perhaps someday, but I didn't think another all-original musical would come around and that I would be suitable for it and want to be a part of it, and with Hugh Jackman!

"This is pretty extra special for me."

Efron was already sold on signing up by the time director Michael Gracey had finished laying out his vision.

"He had this beautiful story depicted, frame by frame, and you could see the movie visually happening.

"How could you not want to be involved? It was fascinating, it was a dream come true."

Months later, as they sit together in a London hotel, it's possible he's still slightly jealous of the trapeze lessons given to his co-star Zendaya, who plays his pink-haired love interest Anne Wheeler.

"I walked into her rehearsals on day one and she was already doing crazy flips and being caught by another dude.

"I was like 'what the heck, did you just know to do this already?' "

She might have made it look easy, but the Spider-Man: Homecoming star says it was anything but.

"I knew I was going to have to be a trapeze artist," she confesses, "I didn't know what that required necessarily.

"I remember I got a phone call from Michael before we went out to New York and he said, 'I want to use the stunt double as little as possible so you might want to start training and working out because not only do I want to see a little bit of physical difference, but I want you to do as much as you can'."

Zendaya says she happily agreed, but inside she was panicking.

"I don't work out ever, that's not what I do. I just have a fast metabolism, so I had to get with it right away.

"It was certainly a change, but I'm very proud of myself."

She was particularly inspired by the example set by Jackman.

"He works his butt off and I think that sets the tone for the rest of the set, for the crew, for everyone that works around him.

"When you see him working hard and never complaining, being extremely nice to everyone and then also being so passionate about the project, it forces everyone else to live up to that and want to be just as good.

"Everyone was there out of passion and love and you could feel that."

The Greatest Showman is out now.