Coldplay doesn’t jump the shark on “Music of the Spheres,” but the British rockers come uncomfortably close. A concept album about a fictional planetary system called The Spheres, the space opera is an uneven mix of synth-drenched power-pop, cosmic interludes (the band goes as far as inventing alien languages) and surprisingly affecting collaborations. It’s the emotional heft of the latter that pumps the brakes as Coldplay approaches that metaphorical Great White, making the band’s ninth album a minor – but not entirely regrettable – addition to an otherwise stellar discography. Space and music have been strange, often very complementary bedfellows since David Bowie dreamed up Ziggy Stardust and those Martian spiders. Astral musings have also occupied Chris Martin’s mind for decades, as he looked to the stars for inspiration as early as the 2000 breakthrough hit “Yellow.” On “Music of the Spheres” (a title Coldplay teased in the vinyl booklet of 2019’s “Everyday Life”), Martin finds himself wondering what an intergalactic band would sound like – a thought that apparently popped into the hitmaker’s mind while watching “Star Wars.” If the resulting album is any indication, the answer is a lot like Top 40 pop radio circa 2021. And that’s not necessarily a bad thing. While veteran acts like Maroon 5 have brazenly owned their hunger for radio hits, Coldplay has juggled the often conflicting goals of credibility and relevance with an unusually deft touch. There’s actually something kind of wonderful about Coldplay channeling A-ha on lead single “Higher Power,” which sounds like a soundtrack cut from a long, lost ’80s movie. Swedish maestro Max Martin, who co-produced the entire album, has a habit of conjuring catchy pop hooks like a magician and, on that front, he’s in fine form on “Music of the Spheres.” The best example of the producer’s pop prowess is “My Universe,” Coldplay’s chart-topping collaboration with K-pop titans BTS. This is a dreamy toe-tapper with the kind of chorus that is so addicting it should come with a warning. “Music of the Spheres” loses its way, however, when the band gets mired in celestial digressions. Alien language interludes, emoji or symbol song titles and a 10-minute closing track distract from the bright and bouncy pop songs. Trying to imbue joyful nonsense with deeper meaning – each song represents a different planet – is emblematic of the album as a whole: overly elaborate and intellectually hollow. “Music of the Spheres” is more effective when Coldplay invites a friend into the band’s sonic kingdom. From Rihanna (“Princess Of China”) to the Chainsmokers (“Something Just Like This”), Martin and company have a knack for bringing out the best in their collaborators. In addition to the winning BTS collaboration, Coldplay teams up with Selena Gomez on the lovely “Let Somebody Go,” a pleasantly understated ballad about heartbreak. It’s new territory for the “Lose You to Love Me” hitmaker and a reminder that Martin is a master songwriter. The track’s shimmering outro is also dreamier than any of the album’s overt intergalactic moments. Equally affecting is “Human Heart,” which is stylized as a heart emoji. A collaboration with rising R&B trio We Are King and U.K. artist/producer Jacob Collier, the choral-like track begins with a haunting a cappella passage before venturing into sparse acoustics and layering that evokes Imogen Heap. Lyrically, the song is about the frailty of the human condition, and the pain and beauty that being afflicted with it entails. For an album that spends so much time imagining the sights and sounds of the heavens, it’s ironic that arguably the best track is inward-looking. If you’re looking for rock, there are slim pickings. “Music of the Spheres” finds Coldplay at its most pop. The closest thing to a rock song is probably “People of the Pride,” which juxtaposes the band’s political opinions with shredded guitars. If it sounds out of place, musically and lyrically, that’s probably because it’s a reworked version of a leaked demo from 2008 “Viva La Vida.” Which elicits an unflattering comparison. Martin is free to follow his muse to the farthest reaches of the galaxy, but there’s no denying that something integral gets lost in the journey.