However, before critics could develop a new case for the contemporary significance of pop music, they had a more basic task in front of them: they needed to revive their own interest in what was truly popular. This was the gist of Kelefa Sanneh’s 2004 New York Times piece, “The Rap Against Rockism,” in which he blasted the critical preoccupation with rock (including such subgenres as grunge and punk) to the exclusion of commercial pop. Since the latter was dominated by brown-skinned musicians, Sanneh argued, this favoritism was essentially racist:

Rockism means idolizing the authentic old legend (or underground hero) while mocking the latest pop star; lionizing punk while barely tolerating disco; loving the live show and hating the music video; extolling the growling performer while hating the lip-syncher. Over the past decades, these tendencies have congealed into an ugly sort of common sense. Rock bands record classic albums, while pop stars create “guilty pleasure” singles. It’s supposed to be self-evident: U2’s entire oeuvre deserves respectful consideration, while a spookily seductive song by an r&b singer named Tweet can only be, in the smug words of a recent vh1 special, “awesomely bad.”

The rockism argument had been circulating among critics since the 1980s. But Sanneh was the first to so acidly and systematically unravel four decades of critical contortions designed to distinguish legitimate pop from bubblegum.

His manifesto was followed by a widely discussed piece in Slate, which raised the banner for what Jody Rosen called “poptimisim.” Rosen denounced any effort to distinguish high from low in pop music. If a writer thinks that Rihanna’s dancehall single “Pon de Replay” is better than the second side of Abbey Road, then he or she should give it critical love. Pavement is noise pollution? Say it. In this way, poptimism restored Christgau’s idea that pop music (and implicitly, pop-music criticism) is an exercise in democracy, precisely because it does not conform to top-down notions of what the culture should look or sound like.

At the same time, poptimism illuminated the degree to which the politics of pop criticism is at loose ends. Writers have historically treated the music as a stand-in for liberation politics, be they sexual (Lou Reed), racial (Chuck Berry), working-class (Bruce Springsteen), or feminist (Ani DiFranco). Poptimism torpedoed such efforts to distinguish politically good music from bad. It also roped in performers whose manipulation of violence, gender, and race don’t fit the standard liberation narrative: Eminem (modern-day Bob Dylan or homophobic misogynist?), Beyoncé (feminist or debased sex toy?), the whole genre of gangster rap (black male empowerment or hyper-capitalist-racial dystopia?). This expansion of the critical canvas, not so coincidentally, put the fun back in pop criticism. What it could not do was define a function for professional critics now that so much of their political ballast had been thrown overboard.

One solution is to focus more intently on musicality. Sasha Frere-Jones in particular has brought a musician’s expertise to his writing at The New Yorker. His 2007 essay on Mariah Carey’s vocal range is an impressive example of this kind of explanatory journalism. But most critics—even those with a grounding in musical theory—are not musicians. For them, limiting the conversation to the technical facility of a pop star is, as Powers pointed out, a little like thinking about a painting as blue.

No, pop music is about the zeitgeist, and pop-music criticism was invented to reveal and critique it. So what can Powers make of the fifteen-year-old girl and the girl’s mother she observed at the Los Angeles Forum, singing along to Nickelback frontman Chad Kroeger’s lascivious lyrics? Just a few years ago, a band like Nickelback would most likely have been dismissed as too commercial, artistically banal, and politically repugnant to warrant critical attention. Now Powers was determined to crack the cultural code of the band, the genre (which she dubbed Flyover Rock), the girl, the fans, and the middle-class world they inhabited.

Jacob Levenson is a writer who lives in Brooklyn. He is the author of The Secret Epidemic: The Story of AIDS and Black America.