Hayley Williams shouted out her Philly-bred producer and cowriter. Then she pulled her on stage for ‘Parachute.’

During the finale of Hayley Williams’ second and final sold-out show at Franklin Music Hall last week, she grinned as a friend entered stage left.

Williams was belting out “Parachute,” the Grammy-nominated track off her hit album, Ego Death at a Bachelorette Party. The fan-favorite single has become a notable part of her show, when Williams will bring her pals onstage.

Williams’ first night in Philly saw cameos from West Philly’s Tierra Whack, as well as comedian Caleb Hearon.

On night two, she brought out the woman responsible for the song’s instrumental track — on the one-year anniversary of it being written: Steph Marziano, who says she owes her career to Philly’s music scene.

Realistically, “Parachute” as we know it might not exist without Marziano. And for the successful, London-based producer and songwriter, that night marked a full-circle moment, performing at a venue that helped foster her career.

Marziano was raised in Marlton, N.J., and attended Cherokee High School. She didn’t care much for school, but throughout her teens, her mom would drive her to pop punk shows at venues like the Trocadero Theatre.

“I discovered music when I was 13 and was fully set on it,” Marziano said. “One of my first ‘big girl’ concerts was Guster at Franklin Music Hall [then the Electric Factory]. By 16 or 17, I knew I wanted to be a producer.”

Marziano champed at the bit at any chance to go to a gig.

“Going to Philly was the first time I saw loads of arts kids in one place,” she recalled. “I realized, ‘Oh my God, there’s a culture here for me. I’m not the weird one.’”

She started interning with Michael Johnson, who led the University of the Arts’ music program. She’d leave school early and learn about mixing and soundboards.

“Few human beings radiate the strength of character, attention to detail, respect for what came before her, and the basic honor that Steph does. That was all there when she was 16,” Johnson said. “I’ve gotten pretty good at identifying the ones that have ye ole ‘what it takes,’ and that was an easy ID.”

At 18, she packed her bags to attend the Liverpool Institute for Performing Arts, which is owned by Paul McCartney. She moved to London, got a studio job, and worked her way up from assistant engineer to producer.

Today, Marziano, 33, is an established music producer, songwriter, and mixer, working with artists including Kevin Devine, Jay Som, and Williams. She splits her time between London and the United States, working in Philly, Los Angeles, and Nashville. Earlier this year, she was in Philly producing out of Will Yip’s South Philly studio, Memory Music.

Marziano and Williams were fans of each other before they worked together: Marziano loved Paramore, while Williams tweeted about the first album Marziano ever produced. What followed was an “instant bond.”

One night at 11 p.m. in London, Williams texted Marziano, inviting her to send an instrumental for Williams to write to. Marziano went to the studio at 6 a.m. By the time Williams woke up in Nashville, Marziano had sent the instrumental to a song that would ultimately become “Creepin’” off Williams’ 2020 debut solo album, Petals for Armor.

From there, Marziano and Williams’ relationship evolved from peers to self-described best friends. They have a tradition of getting ice cream anytime they’re together.

Last week in Philly was no different. Tierra Whack invited Williams to an ice cream social after the first night of the Ego Death Philly tour leg. Marziano was there. Williams invited her to join her the next night onstage.

It seemed fitting. Marziano wrote the instrumental to “Parachute” for Williams about a year ago. Marziano had sent the singer something she had been working on, and soon after, she was on a flight to Nashville. The duo worked on the track alongside Daniel James, who produced and wrote the rest of Ego Death with Williams.

“We spent a day working on the bridge. We wanted it to be really big,” Marziano said. “Hayley joked that it was our ‘Bohemian Rhapsody.’”

The track’s success was a pleasant surprise for Marziano, who came in at the eleventh hour of Ego Death, with most of the album already demoed and final versions ready to be recorded.

And the song wasn’t part of Williams’ initial release. It was added as a sort of bonus track as part of the full album’s streaming release in late August. About a month earlier, Williams had released 17 standalone singles, excluding “Parachute.”

When the single dropped, it was an instant success, receiving widespread praise from music critics and earning a Grammy nomination for Best Alternative Music Performance.

“We knew we were onto something, and obviously, you hope all your songs are perceived well,” Marziano said. “But you don’t know how great it is until it’s real.”

Last week in Philly, as Williams performed two sold-out shows at Franklin Music Hall, Marziano and her family were in attendance.

Cut to night two, when Marziano was onstage.

“It was all adrenaline,” she recalled. “It just flowed. [Williams] is such an incredible frontperson, any nerves I had were immediately gone.”

The pair screamed, giggled, embraced, and danced together. At one point, they both ended up on their knees, bowing to one another, with Williams cradling the back of Marziano’s head. Marziano called it “serendipitous” and “one of the biggest highs of my life, even though it was only a minute long.”

“There was this beautiful moment of realizing, ‘I used to go to rooms like this and dream of these places,’” Marziano said. “This is where I started.”