After 30 years fronting The Pretenders, it’s remarkable that Chrissie Hynde has produced arguably her finest work at age 59. She has spent the bulk of her career setting musical trends and breaking boundaries in the rock and new wave arena. The Pretenders were inducted into the Rock and Roll Hall of Fame five years ago, making her one of the few female bandleaders to enter that pantheon. She’s also been outspoken as a vegetarian and animal rights activist.

And yet Hynde’s latest work stands up to any and all of her past achievements. That’s due in no small part to her affiliation with Welsh producer and singer-songwriter JP Jones, who, in his early 30s, is only a year or two older than Hynde was when The Pretenders released their debut album in 1980.

The pair’s new band, JP, Chrissie & The Fairground Boys, recently released the gripping debut CD “Fidelity!” They’ll travel to the Seacoast in support of the album on Thursday, Sept. 30, for a show at The Music Hall in Portsmouth.

The story of how Hynde and Jones met unfolds in the song “Australia,” the fourth track on “Fidelity!” Jones drunkenly approached Hynde at a party in London in 2008 and introduced himself. The two hit it off and continued corresponding by phone. When Jones sent Hynde a text message whishing her “all the fairground luck” prior to a show, she responded by encouraging him to write a song called “Fairground Luck.” He did so, and sent it to her the next day. It’s the third track on “Fidelity!”

After finishing up a final tour with The Pretenders in 2009, Hynde invited Jones to join her on a week-long songwriting retreat to Havana.

“She just said one day, ‘Do you want to go to Cuba?’” Jones recalled. He took her up on the offer, and an unlikely relationship was born. But, with a 28-year age gap, they were under no illusion that their whimsical romance would last.

“We just sort of adored each other. But we realized we couldn’t start a family together, and I’ve always wanted to have a family,” Jones said. “We wrote a whole album about the fact that we couldn’t do that.”

With 11 original songs, the CD is like an ongoing lyrical dialogue between Hynde and Jones, expressing the potent mixture of passion and heartache that has resulted from their musical and personal connection. The opening lines of the first song, “Perfect Lover,” instantly capture their predicament.

“I found my perfect lover, but he’s only half my age / He was learning how to stand when I was wearing my first wedding band,” Hynde sings. “I found my perfect lover, but I have to turn the page / But I want him in my kitchen and standing on my stage.”

Jones sings backup vocals on the track, often responding directly to Hynde’s words. It’s as if they wrote the song by passing a sheet of paper back and forth and trading lines. According to Hynde, that’s not far from how the process went in Cuba.

“We would be sitting in a restaurant eating rice and beans and scribbling on a napkin,” she said. Later, Jones would go for a swim while she relaxed in their hotel suite (“I don’t like the sun,” Hynde said), and they’d both come up with more lines to share. “It is very conversational. The songs are written to each other and about each other.”

After five days in Havana, they returned to London and put together a demo. Listening to the recorded songs, they were awed by the results. “I said, ‘Wow, this is like the best stuff I’ve ever done.’ And he felt like that, too,” Hynde said.

Even as they polished off the album, they remained aware that their enduring relationship would only be musical in nature.

“We don’t have a future together as a couple. We haven’t ever been a couple. The only future we have together is being in a rock band together,” Jones said.

Their conflicting emotions, and their painful awareness of their gaping age difference, are apparent throughout the disc. “His time is tomorrow, mine was yesterday,” Hynde sings in “Perfect Lover.” Jones later vents his lovesick frustration in “Leave Me If You Must.” “I’m jealous of your future, I’m jealous of your past / In a temporary world where nothing’s meant to last,” he sings. But they harmonize on a resolute refrain in “Courage.” “They got it wrong when they said that we were done,” they sing in unison.

The music sounds largely like a fermented version of The Pretenders’ style, infused with hints of alt-country and indie-folk, but with a fairground quality Hynde described as “carney.” Her new wave proclivities shine through on certain tracks, including the second song “If You Let Me”—a definite highlight (check out the music video on the band’s Web site, a short film blatantly modeled after the Swedish vampire flick “Let the Right One In,” complete with an exceptionally gory climax).

Hynde’s transfixing voice belies her age. She sounds not much different from how she did in the early ’80s, with a touch of world-savvy wisdom. Jones complements her smooth delivery with an affected rasp that makes him sound older than he is, like Bon Jovi after six packs of cigarettes.

The collaboration has helped Jones emerge as an artist deserving of the solo spotlight. His former band Grace released an album on EMI in 2007 and spent two years touring the U.K., but the group split when their label dropped them in 2009. Jones became disillusioned with attempts to market him as a budding pop star.

“I was kind of pushed and pulled back home when I went solo. I left another record deal back home. I walked away from it because I didn’t want to be told what to do,” he said. “Chrissie made me realize that you’ve got to be true to yourself, in life in general and especially in rock and roll music.”

The partnership has also proved beneficial for Hynde, who has approached the project with a renewed sense of vitality. “Fidelity!” marks the first time she’s cut an album without The Pretenders, which has gone through numerous lineup changes over the past three decades. Loosening her many responsibilities as a bandleader has been “exhilarating,” both in the studio and on tour.

“I’m delighted to get onstage and not have to refer to any kind of past songs or anything.

It’s great, it’s liberating,” she said.

Jones’ sunny and gregarious disposition has also rubbed off on Hynde, to a degree. Although she’s previously worked with the likes of Emmylou Harris, Elvis Costello, U2, Morrissey, Sheryl Crow and even Frank Sinatra, she said interacting with Jones has helped open her up to deeper collaborative possibilities.

“He’s much friendlier and sociable than I am. It brought me out of my shell a little bit,” Hynde said. “He’s more of a collaborator than I am. I’m just more of a hermit, and I’ve certainly never done anything like this... I think he could write with your mother-in-law and come up with a good song.”

She’s also enjoyed touring the United States with Jones and their four other European band members, whisking them around her native country.

“It’s like taking someone back to your hometown who’s never been there before. Everything seems new,” she said.

Jones said the audience response so far has been “out of this world.” He’s already reached a natural comfort level with Hynde onstage, and touring the States has been surreal for his entire band.

“It’s been amazing. It’s just like singing to each other. It’s like we’re having a conversation, like you’ve been playing with your best mate,” he said. “It’s been a dream for the band and me forever.”

Jones said the pair already has enough material to record another album, and Hynde looks forward to writing more songs with her new partner.

“We’ll probably go off and isolate ourselves for another five days like we did in Cuba and keep writing,” she said.

The concert begins with opener Amy Correia at 7:30 p.m. on Sept. 30 at The Music Hall, 28 Chestnut St., Portsmouth, 603-436-2400. Tickets are $26 to $38. For more information, visit www.themusichall.org.