When people think of Funny Girl, they tend to think of Barbra Streisand. She played the lead role in the 1964 Broadway musical and made her film debut in the subsequent 1968 film version that won her the best actress Oscar (tied, in the only such instance, with Katharine Hepburn, who also won a record-setting third best actress Oscar, for The Lion in Winter).

But despite that star-making performance, the show isn't about Streisand. It's a fictionalised musical biography about Fanny Brice – the real-life comedian, Broadway and film star – with a score by Jule Styne and Bob Merrill including People, Don't Rain on My Parade and I'm the Greatest Star.

Vanessa de Jager, who plays Brice, says, "It's about her life and her journey: she wanted to be a star."

While de Jager is mindful of the long shadow of Streisand in the role, she's not daunted.

"I love Barbra," she says. She's done her research into Brice as well as Streisand and says she's "tried to find a bit of a mix" with elements of both approaches – given the show was about one star and written for another – "and Vanessa in the middle: a mash-up".

Funny Girl follows Brice from her life as a teenager growing up with her Mama (Michelle Klemke), a saloon-keeper in Brooklyn in the early 20th century. to her early struggles to establish herself in show business. She starts off in vaudeville with the encouragement of her friend, dancer Eddie Ryan (Will Huang) and eventually rises to stardom in the Ziegfeld Follies and forms a relationship with gambler Nick Arnstein (Joel Hutchings). But while her career seems to be ever on the rise, her personal life doesn't go as smoothly. Can Fanny and Nick find happiness?

Director Jarrad West says Funny Girl played "such a wonderful part in my growing up". "What self-respecting homosexual boy didn't sing along to People or Don't Rain on My Parade? It's such an iconic musical."

And while the show may be deeply unreliable as biography – it ignores Brice's first husband, for example, and much of the reality of the portion of her life that it covers – that isn't terribly surprising : whether it's Gypsy, The Sound of Music or Hamilton, any real-life-inspired musical is going to fiddle with the facts, whether for dramatic effect, legal reasons or time constraints.

West says Funny Girl is "such a classic love story" from a time when book musicals were the norm, with well-developed scripts and characters rather than just a few lines between each song to keep the show moving.

"If you've never seen Funny Girl you don't know where it's going to go," West says.

"It doesn't end up where you think it's going to end up."

And while the storyline is obviously similar to that of the movie, there are differences, too, with some songs and characters omitted or sidelined in the film given their due here.

De Jager says, "The show is a very emotional journey, especially in the second act, which gets quite heavy."

Hutchings agrees. "I was surprised," he says. "I expected it to be lighter."

The relationship between Fanny and Nick is one of true love but their problems are genuine and appear to be insurmountable.

But whatever happens, for Brice one thing remains constant, de Jager says: "The show must go on: she's going to get through it."