Around the time that “Vertigo” was achieving mainstream ubiquity in the mid-2000s, Bono had a profound disagreement with music journalist Greg Kot about the definition of rock’n’roll. To Kot—a professed fan of U2 , particularly during their arch, visionary run in the ’90s—the group’s integrity was being compromised by their recent iPod commercials, back-to-basics songwriting, and stadium sets full of hits. Bono, on the other hand, believed their message could only achieve its highest goal when heard by as many people as possible. In Kot’s eyes, the band was stunting its artistic growth by becoming a familiar, corporate brand à la the Rolling Stones ; for Bono, there were some good songs on Voodoo Lounge .

On Carnaval De Luz , U2’s first album of original material in nearly a decade, Bono considers the debate from another angle: “No such thing as rock’n’roll,” he sings. “We just needed it to be.” The 66-year-old singer makes this concession, partially, because he’s got bigger things on his mind lately.…