For creator Garry Marshall, a Happy Days musical had been in the back of his mind even when the series was airing on US television.

“We used to do a lot of musical shows in the TV series,” he says from the five-star London Goring Hotel, having flown to the UK to see the British premiere of his musical at Bromley.

“It has been a long journey for [composer] Paul Williams and I.”

An arena show version of Happy Days using rock and roll classics toured Australia in the 1990s but Marshall began work on his own musical, using long-time collaborator Williams’s original songs, in the mid-2000s.

His version made its US debut at Marshall’s own Falcon Theatre in Burbank, California, before runs in Connecticut and New Jersey in 2007 and 2008 – eventually going on a national US tour.

Marshall is still making improvements to his creation.

“We are still tweaking one line – where the real name of one of the tough guys, the Malachi brothers, is revealed,” says Marshall.

“In the US it was Myron, a really nerdy name, but it doesn’t really work in the UK – we’re trying out Herbert, Eugene, Nathan... we’re always working!”

Marshall’s long career has seen him direct 17 movies, including Pretty Woman, Beaches and both Princess Diaries, as well as produce the hit US TV shows Laverne And Shirley, Mork And Mindy and The Odd Couple.

But Happy Days holds a very special place in his heart.

“All my other shows I did with other people,” he says. “I created Happy Days on my own, with the help of the cast and writers. I really did it for myself – to see it still going is a wonderful thing.”

The 1950s setting was both a nostalgic exercise and a tribute to a period which was very important in Marshall’s own life. This musical has been very carefully positioned in 1959.

“This was the last quiet before the storm of the 1960s,” says Marshall.

“It was difficult to do a show about teenagers in 1974 without drugs and booze and craziness – the guys at the network wanted something for the family. The 1950s was a quieter decade, where things were clearer and kids were allowed to grow up.

“For me, I had served in the army in Korea for two years and came back in 1959 to start my life back again. It was a special time for me.

“I graduated high school in 1952, graduated college in 1956 and got my first real job in 1959 on The Tonight Show with Jack Paar.”

The rose-tinted vision of the 1950s was based around the Cunningham family, presided over by hardware-store owning patriarch Howard and his caring housewife Marion – Marshall’s self-confessed favourite character who is being played in the musical by Cheryl Baker.

“Happy Days was about love, family and friendship,” says Marshall today. “The friendship was the strongest between The Fonz and Richie [the Cunninghams’ son, played in the series by Ron Howard].”

The Fonz, being played in the musical by Emmerdale’s Ben Freeman, was based on several people Marshall grew up with in The Bronx.

“Those guys didn’t say much – they just hit you in the head mostly,” he says, highlighting “a guy called Pete Wagner who had a motorcycle” as a major inspiration.

Childhood inspiration

“I grew up in a neighbourhood where you could either play football, hit somebody or wear nice clothes. Both Ralph Lauren and Calvin Klein came from my neighbourhood.”

The Fonz had started out as a minor character in the series and Marshall credits Henry Winkler – creative consultant for this UK tour – for bringing him out of the shadows.

“He was a wonderful actor,” says Marshall. “He said he had to react to things in the scenes, so we said he should make a gutteral sound – which became part of America. He became a break-out character – not something we predicted at all.”

When it came to writing the book for the musical, Marshall had to boil ten years of stories down to create a two-hour narrative.

“Visually it had to be set at Arnold’s malt shop,” he says. “Fonzie’s love affair with Pinky Tuscadero [played by Sugababe Heidi Range in the musical, and Roz Kelly on TV] was always one of our strongest stories.”

The 24-date tour of Happy Days: A New Musical, featuring an impressive 17-strong cast, has been part crowd-funded on the internet, underlining the affection the show still holds in the UK.

Marshall is pleased with how director and choreographer Andrew Wright – who has previously worked on Chichester Festival Theatre productions Barnum, Singin’ In The Rain and 42nd Street – has added his own stamp to the production.

“The dancing is terrific,” he says. “Andrew is an amazing choreographer, it really makes it quite a musical.”

And Marshall is hoping the show has more life in it, with dreams of taking it to Australia in the future.

“So many people say they love Happy Days,” he says. “They loved the fantasy.

“I’ve met people who say they had a terrible childhood – being abused or left by their parents – but they would watch Happy Days to see how it could be. I’m glad I was able to help people in that way.”