Relentless is the result of a collaborative effort between Chrissie Hynde and her band's resident guitar hero, James Walbourne, who, when he's not working with Hynde, is always in high demand, known for his work with artists like Dave Gahan, Jerry Lee Lewis, the Rails, and more. The announcement of Relentless came back in May, accompanied by the album's first single, "Let The Sun Come In." The song, marked by its electrifying energy and unique perspective, signaled the Pretenders' return to Warner Music Group after more than two decades, where their journey first started when they were signed to Sire Records by the legendary Seymour Stein.

Produced by David Wrench and recorded at Battery Studios in West London, the album boasts 12 tracks featuring what Hynde calls "The Pretenders Collective." This extended band includes Walbourne on guitars, Kris Sonne on drums, Chris Hill on double bass, Dave Page on bass, and Carwyn Ellis on keyboards and guitars. Relentless also fulfills a long-standing wish with special help from Radiohead's Jonny Greenwood, who provides the string arrangement and conducted the 12 Ensemble for the album's beautiful closing track, "I Think About You Daily."

Hynde expresses her excitement about working with Greenwood, saying, "I met Jonny a couple of times, and we’re obviously big fans of him because he’s done some incredible music over the years. I saw him at the Phantom Thread premiere where the film was running on screen with a live orchestra playing. And we spoke afterward, and he expressed an interest in doing something one day. I was thrilled and very surprised. He also came down to see a Valve Bone Woe show we were doing in the basement of a Pizza Express. So when we discussed the idea of getting strings on 'I Think About You Daily,' he was the first choice. Legend!"

For Greenwood, working with Hynde was an honor. He states, "It was a genuine honor to score strings for Chrissie. The arrangement wrote itself because of THAT voice. She’s one of the greatest singers in popular music, and her continuing passion for creation was an inspiring experience from first the email to the last note of the recording."