Coldplay had the wind in their sails as they arrived at their fifth record. 2008’s Viva la Vida or Death and All His Friends had made for an exhilarating course correction after the uncertainty of 2005’s X&Y and here they seemed emboldened by the momentum their fourth record had generated. Mylo Xyloto is the sound of Coldplay fully embracing their status as one of the world’s biggest bands, a record that introduced a sense of spectacular into the mix where everything—the Day-Glo artwork and style, the luminous sonics, the silly title—feels pushed to the utmost degree. It’s Coldplay at their most bombastic. It could have headed in the opposite direction, though. The original plan was to make a stripped-down album that would hark back to the stark introspection and acoustic guitars of the early work. But big tunes that deserved big production kept arriving and Chris Martin, Jonny Buckland, Guy Berryman and Will Champion found themselves writing two records that differed in sound and vibe. It was working on a raw, accordion-led version of “Charlie Brown” that put an end to that notion when Berryman suggested it was madness not to do it as a panoramic rock-pop sing-along. The acoustic record was shelved and, in its wake, came Mylo Xyloto. The finished version of “Charlie Brown” featured no accordion. Instead, it sounded like Achtung Baby-era U2 being launched into space. A concept album set on the fictional planet of Silencia and telling the tale of a war against sound and colour—can you tell that Coldplay were embracing the spirit of theatricality here?—Mylo Xyloto saw the quartet brighten their sonic palette with the kaleidoscopic sound of modern pop, where their trademark shimmering guitar lines and muscular rhythms are elevated by strobing synths, R&B beats and layered soundscapes. The dynamic production would count for nothing without rapturous hooks to hang everything on, though, and Coldplay had them in spades. The swirling melodrama of “Paradise” was their best pop moment, yet that was given a run for its money by the Rihanna-featuring electro-pop euphoria of “Princess Of China”, while the cosmic rave thrust of “Every Teardrop Is a Waterfall” showed they could still do yearning on such a grand canvas. The smattering of lower-key songs throughout the record— the round-the-campfire strums of “Us Against the World”, “U.F.O.”’s finger-picked folk, the glacial contemplation of closer “Up With the Birds”—were just as essential, gear changes that gave the album its bearings. Perhaps aware that they had taken this sound as far as it could go, they changed tack on their next record, but Mylo Xyloto had already had the desired effect. This was the album that blew Coldplay’s sonic horizons wide open.