Ever since 1920s marketers categorized some discs as race records and others as hillbilly American music genres have been constructed around race. That's true today of indie rock and indie music, genre designations that are occupied almost entirely by white musicians. "In indie rock, white is the norm," Sarah Sahim wrote last week in a Pitchfork about "The Unbearable Whiteness of Indie." She later added, "I can count on one hand the prominent performers in the independent scene that look like me."

Sahim argues that there are so few artists of color in indie because of "overt and covert expressions of racism." She points to a petition calling for the Glastonbury music festival to replace Kanye West as a headliner with a "rock band"—which is code, Sahim rightly argues, for "a white artist." When you're an artist of color and you see indie fans signing petitions like that—with 132,000 signatures, at last count—you're going to get the message that you're not welcome in indie.

One way that indie maintains its whiteness, then, is by telling people of color to go away. But the fact that "rock" can be code for "white" suggests that genre whiteness is not just a matter of discouraging artists of color. Genres like rock and indie are for many people defined by whiteness—that is, white skin becomes the genre marker, rather than the music itself. There are few artists of color in the indie scene because artists of color who make what could be called "indie music" get classified as something else.

This is true of Kanye himself. Yeezus, his most recent album, is a swaggering left-field electronica soundscape with hip hop elements. So was Beck's major-label debut, Mellow Gold. The latter is considered an indie classic (even then, in 1994, "indie" was no longer define by whether the music was put out by an independent label). Kanye's album is considered a hip-hop classic, or pop classic, or electronic classic—anything but an indie classic.

The whole hipster R&B genre, aka "PBR&B," seems designed to avoid labeling black artists as "indie." Performers like SZA, FKA Twigs, or Dawn Richard all work with spacious, off-kilter beats and psychedelic electronica flourishes—they sound like peers of Bjork, not Beyoncé. But Bjork is considered central to indie, and SZA, FKA Twigs, and Richard are all R&B with an asterisk. Or consider Valerie June, a guitar-based performer who works with an eclectic variety of roots sources in contemporary idiosyncratic settings. She's not so different from the Dirty Projectors or Vampire Weekend, but June is classified as blues or roots music. The color of her skin means that she's invisible to, and as, indie.

There are exceptions, of course. Sahim cites M.I.A. as the rare POC in indie, and there certainly have been black rock artists, like Jimi Hendrix. Genres are amorphous and porous categories; they aren't determined by any one characteristic, but by what sci-fi scholar John Rieder calls a "web of resemblances." So a black performer like Charley Pride can be a country artist through choice of repertoire, collaborators, venues—a range of markers which signal "country." But none of that changes the fact that one important, and often central, way that people are sorted into the country genre is by skin color. In a 2008 essay, scholar Geoff Mann argued that in many ways the purpose of country was to "recruit white people to their 'whiteness.'" White people aren't the only ones who perform country, or indie, or rock. But country and rock and indie are still iconically white—both because the default, stereotypical performer is white, and because default, stereotypical whiteness is in part defined by those genres.

In the collection Hidden in the Mix, various scholars point out that whiteness in country is defined as the default; white is normal, and so non-white performers become marginal to the genre, even when those performers (like Ray Charles) are best sellers. The same is true in indie. A white artist like Moby can use gospel samples and be credited for his broad taste in non-white music and his genius in making them "contemporary." Black music is an influence, to be recuperated and packaged in whiteness. In that context, black performers become curiosities and footnotes: When a black artist like Jordannah Elizabeth uses vocals influenced by gospel performers in a setting with high-gloss R&B electronica production, as on "14 Minus 13," or when Dawn Richard references Peter Gabriel, indie doesn't have a ready conceptual framework—which is perhaps part of the reason why Moby is so much more popular than the black artists who perform comparable appropriation in reverse.

Dee, a critic who writes at the fyeahblackmusic tumblr, told me in an interview that "the real interesting thing I've always thought about rock and roll is its mix of black and white roots. And I think that's what scares people. You end up in a situation where the black part of rock and roll becomes the unspoken part. So you get white people pushed out in front as innovators. And the black part is still there, but is unspoken…. There's a level of erasure happening because the idea of a mixed America is something that doesn't sit right with many folks in America."

Dee is talking about rock music, but it applies to indie as well. Iconically black music genres, whether jazz or hip hop or blues or soul, are consistently integrated; white performers like Bennie Goodman, or the Beastie Boys, or Stevie Ray Vaughn, or the Muscle Shoals session musicians, have been successful, central, important—no one creates sub-genres to put an asterisk by their names. Iconically white genres, though, work to keep their whiteness, a practice that marginalizes black performers and narrows the genre.

If indie wants to stop being unbearably white, its musicians, fans, and critics should stop defining the genre through whiteness. If indie means independent music, then all those hip hop mix tapes should count. If it means Bjork, then it should mean Dawn Richard. If it means guitar rock, then Valerie June should count. And if these changes shift indie's center in the direction of new, unfamiliar sounds or subgenres, all the better. Diversity isn't just a cosmetic change; to open your community is to change your community. And who knows what indie music could be if it were to allow itself to see, or hear, all the ways it isn't white?