“Hold on,” says Mike Sardina (Hugh Jackman), on a landline call in Wisconsin, circa 1995. He turns to his teenage step-daughter Rachel (Ella Andxerson) and—much to her horror—asks, “What’s a pearl jam?” 

Craig Brewer’s “Song Sung Blue,” based on Greg Kohs’ documentary of the same name, dramatizes the incredible love story of Mike and Claire Sardina. The two meet as impersonators at the Wisconsin State Fair. Mike, a mechanic known by the stage name “Lightning,” rightfully balks at filling in as Hawaiian icon Don Ho. Taking the stage as red-satin and fringe-clad Patsy Cline, hairdresser Claire (Kate Hudson) suggests he try Neil Diamond. The two find a deep connection through overcoming past traumas—he’s 20 years sober and she’s struggled with mental health—and their shared passion for music and performing.

Mike takes Claire’s suggestion and the two partner on a tribute band: “Lightning & Thunder: the Neil Diamond Experience.” They also become life partners, and blend their families: Mike’s teen daughter Angelina (King Princess) and Claire’s young son Dana (Hudson Henley) and daughter Rachel. Angelina and Rachel immediately bond over parenting their parents, and their affinity for flannels, striped baby-Ts, and slouchy denim—a sign of the grunge-y times. Well, almost.

“I was looking at '90s Nirvana and all of that, but how they were doing it in Wisconsin—lots of plaids, jeans, and acid wash,” says costume designer Ernesto Martinez. “The acid wash jeans were already out [of fashion] by then, but we still were wearing them in the Midwest.”

Rachel, who probably just bought the “Vitality” CD from Sam Goody at the mall, obviously knows the Seattle grunge pioneers—and verifies that Eddie Vedder (John Beckwith) is on the other end of the call. The frontman proceeds to ask a somewhat bewildered Mike if Lighting & Thunder would open for Pearl Jam at their upcoming Milwaukee show. Never have parents been so cool—or maybe not. 

“Our director Craig and I just thought Mike and Claire would wear something so inappropriate to a Pearl Jam concert,” says Martinez. “Like they have no idea really what Pearl Jam or grunge is about.” Sure enough, Mike’s clad in a red plaid flannel, as he resumes Eddie’s call—“Yeah, Lightning, speaking…” But Mike’s the only one wearing it authentically. “That was what he wore to work as a mechanic. He wasn't copying grunge,” says Martinez. “Grunge was copying him.”

Mike’s been commanding the Lighting & Thunder stage in his signature of sequin vests and coordinating billowy shirts dating back to Diamond’s peak sparkle-period in the ’70s. Martinez also studied documentary footage of the real Mike to custom-design upwards of 51 costumes, including an American flag sequin vest. “I made it work for Hugh Jackman,” he says. “I hate saying it, but I had to make him not so handsome.”

Claire recruits her hairdresser colleague/amateur stylist to design her shimmering, coordinating, and very early-to-mid ’80s stage dresses. For their first bar gig—which goes awry, thanks to an unruly biker crowd that doesn’t appreciate Mike’s esoteric interpretation of Diamond’s 1970 deep-cut, “Soolaimón”—Claire wears a black and silver sequin mini-dress with chevron fringe and studding along the deep plunge halter neckline.

“In the beginning, speaking to the script, she looks like ‘eye candy’ for Lightning,” says Martinez. “But as the story progresses, she becomes more of a backup and support system to him. She’s more covered, but still glittery and shiny. Just little subtle changes.” 

For a montage of exhilarating shows, Claire wears a rotation of long-sleeve and fully sequined dresses in a range of colors, often matching Mike: gold, silver, blue, and red. She also sings and plays keyboards in a fabulous leopard print, power-shouldered blazer over a keyhole neckline dress. Martinez enjoyed tapping vintage vendors in Detroit, Michigan, and New Jersey for Claire’s radiant wardrobe. “Kate is just a great person to work with. She's just down for anything,” he says.

For the big Pearl Jam concert, Claire and Mike would obviously up their ultra-embellished, flamboyant, and still very ’80s “Dynasty”-esque game. “I thought, ‘Well, why don't we just go over the top?’” says Martinez. The Sardina family makes a grand, pre-show entrance, with Rachel and Angelina bringing up the rear in their best “Reality Bites”-era Winona Ryder and slip-dress-wearing Courtney Love. Mike strides confidently in red monochrome and a sequined vest, with Claire countering in a cerulean-blue drop-waist midi-dress, with a glimmering diamond-shaped embellishment on the draped bodice. “Claire’s full on-glam,” says Martinez. “She wears a fur coat she got at a thrift store because they don't really have money. Their ‘stylist’ probably made that dress.” 

He actually worked his magic on an ’80s-vintage confection under the faux fur coat. “I doctored it up. Everything had to be either toned down or toned up,” says Martinez, who added the ruching and beading, and statement shoulder pads on the split cap-sleeves. “Let’s make them exaggerated!”

Eddie Vedder joins Mike and Claire on stage for a powerhouse rendition of Diamond’s “Forever in Blue Jeans,” as Rachel and Angelina go wild singing along in the audience. In real life, Vedder stumbled across Lighting & Thunder performing at Milwaukee Summerfest in 1995, and joined them onstage for an impromptu rendition of Diamond’s 1978 ode to denim. For the dramatized movie moment, Martinez recreated the Pearl Jam lead singer’s “Cramps” t-shirt, board shorts, and Doc Martens. “I love Eddie Vedder,” says Martinez.

The real Rachel, Angelina, and Claire were a regular presence on set. The latter even showed Martinez a bootleg t-shirt, which was reimagined for the movie as a Lightning & Thunder poster in the plug, “as seen with Pearl Jam.” The trio also gave Martinez the biggest stamp of approval. “They would see Hugh and Kate come out, and run over to me and say, ‘Oh, my God, I love what they're wearing’ and ‘I would wear that!’” recalls Martinez, who even styled Claire Sardina in leopard print for a NYC performance. “That was my last check off.”