When the subject of a Broadway show is an icon of both music and fashion, it’s vital that the piece be dazzling both visually and aurally. To ensure this was the case for The Cher Show, now playing at Broadway’s Neil Simon Theatre, the creators and producers went straight to the man who has helped the titular superstar — and many others — look fabulous for decades: legendary designer Bob Mackie.

When tapped to craft costumes for The Cher Show, Mackie says, “I knew it was going to be pretty big. I’ve known Cher and designed clothes for her for the past 50 years, so that’s a lot of costumes and show-stopping outfits. We’re not featuring them all, but we are trying to hit the highlights.”

Mackie cites the sartorial sensations Cher has showcased at Academy Award ceremonies through the years, noting that Stephanie J. Block, who plays “Star” — one of three actresses who play the singer, actress, and force of nature, born Cherilyn Sarkisian — “gets to wear them all. It was really fun to re-create the looks these many years later.”

In addition to his backstage role, Mackie is also featured as a character in the new musical. “It’s actually amazing being portrayed on the stage by someone else,” he says. “It never occurred to me that it would happen, but I’m very flattered they thought I was important enough to put me into the show.” He notes that Michael Berresse, who plays him, is a veteran Broadway actor who “can sing and dance, and he’s handsome, so that’s a good thing.”

Berresse, who also is a director, quips he is “old enough to remember The Sonny and Cher Show” — as well as The Carol Burnett Show, whose star has also championed Mackie from early on. So the performer grew up idolizing the designer. “He’s not just a fashion brand, he’s an American icon,” Berresse says of Mackie. “His name was like a magical incantation to me as a child, so it’s crazy that my life has led me to even knowing him personally, let alone playing him.”

Mackie has been a regular presence at rehearsals, Berresse adds. “Having him there day-to-day connects us to Cher and the history of her life. He started working with her when she was a teenager, and though he’s only maybe seven years older than her, he’s really been kind of a father figure to her, someone she feels safe with.” Personally, Berresse has found the designer to be “a very humble and shy and very kind person. What did not surprise me, and what has delighted me the most, is his joy. Some people never lose their connection to that youthful sense of joy. I think that when Bob is designing, it’s like a kid playing with a Christmas toy.”

Berresse, who also has a turn in The Cher Show as director Robert Altman, who gave crucial support to Cher’s acting career, describes his portrayal of Mackie as “a heightened musical-theater version of him — in Bob’s own words, a sort of ‘dream Mackie.’ It means a great deal to me that the audience see his kindness and joy and wit amplified. Bob isn’t a grandstander or a showoff as a man, and he can be wicked and wry, but he’s never mean. He can be sassy, but not in a public way.  It’s my job to keep his buoyancy, to find something joy-based in every line.”

The actor points to a scene in the musical in which the character of Mackie is “at a fitting with Cher, and she’s at a point in her life where she’s feeling a little stifled by all the men she has to answer to. She resents being told what she can and can’t wear, and of course Bob does too, and they sing a song together, and there’s a parade of costumes, one after another, each more shocking and extravagant and colorful and hilarious than the next. The audience just loves it, and I love how they get to show their immense gratitude for Bob. If he’s in the house, I always try to make eye contact with him.”

For Mackie himself, The Cher Show reaffirms one of his most cherished collaborator’s own enduring savvy. “When you start looking back, you will see that Cher influenced fashion in a big way,” the designer says. “It was over-the-top, but Cher wasn’t interested in looking like a housewife in an evening gown; she wanted to be Cher, and she manages that just fine. I think Cher is a style icon because she’s unique. There’s nobody else quite like her. I keep seeing her style influences popping up here and there, and that’s really flattering — flattering to me and flattering to Cher.”