Perez Hilton waded into social media criticism this week after the outspoken blogger tweeted about Mariah Carey’s latest album, Caution. The album was released in early November, and Hilton bemoaned the supposed lack of attention the project is getting while offering advice as to how Mariah can get back to her chart-topping ways.

“In case you didn’t know, Mariah Carey has a new album out today,” Hilton tweeted. “Sadly, she isn’t expected to debut in the top 5 on the Billboard Hot 100.”

He proceeded to chastise the legendary diva for not making the kind of music “fans” want to hear from her.

“And another way she’s not catering to her base!” he responded after a fan called Caution a “great R&B album.” “I’ve always preferred my Mariah pop. Her best work has consistently been her pop output.” He went on to say, “Pop music is vast. I’m not saying go for radio or go dance. I’m just saying that R&B Mariah is so played out. She’s done that for over a decade now. I think many of her old fans miss the other kinds of songs.”

Perez’s belief that “pop music is vast” while “R&B Mariah is played out” suggests that he sees pop as a wide-open genre but views R&B through a much more limited lens. That’s telling, considering that R&B has been a broad school—for decades. The swinging piano of Ray Charles, the soulful grit of Otis Redding, the Supreme’s catchy hooks, the dapper crooning of the Stylistics, the kinetic new jack swing of Bobby Brown, the pulsing grooves of Usher—that’s all been R&B. That a genre so varied is still viewed as a box to break out of says more about our ideas about genre than it does about the style itself.

Similarly, our ideas of what constitutes “pop” vs. “R&B” are often filtered through a prism of race—and race plays heavily into how that music is marketed. If Celine Dion is “pop” but Butterfly-era Mariah is “R&B,” then what does that make millennium-era acts like Britney Spears, ‘N Sync and Christina Aguilera? At the time, they were all credited as the vanguard of a pop boom that dominated music at the dawn of Y2K. But they sound a lot more like Mariah than Celine. “Pop” is obviously more than middle-of-the-road adult contemporary music. So do the parameters get more rigid once we’re talking about a black artist? Early ’90s Mariah Carey’s brand of adult contemporary balladry wasn’t that far removed from artists like Patti Austin and Peabo Bryson—yet they’ve rarely been marketed as “pop” singers.

After he was told that Mariah’s early work was actually R&B, Perez disputed the idea—offering his own take on her blockbuster debut’s stylistic classifications.

“That first album was def soul and pop,” he tweeted. “I don’t think most would call ‘Vision Of Love’ R&B.”

That somewhat ahistorical take reveals just how muddy our contemporary ideas of genre are—and how convoluted many of these terms have always been. “Soul” was a term that was largely out of fashion in the late-’80s, a distinction that had been supplanted by “R&B” in the post-disco, pre-new jack period of the mid-’80s. When rappers railed against the pretenses of black radio, an institution that was famously resistant to hip-hop throughout the ’80s, they threatened to pull the plug on “R&B,” not “soul.” “Soul” regained prominence as a term via Mary J. Blige (dubbed “The Queen of Hip-Hop Soul”) and later, singer-songwriters like D’Angelo and Erykah Badu were marketed as trendy “neo-soul.” Soul came back into the cultural lexicon with this new generation of artists as realness and grit became necessary components for the re-emphasis on authenticity in the music. If early Mariah was “soul,” then Butterfly-era Mariah would best be described as “hip-hop soul,” like the then-popular sounds of Blige, Dru Hill and R. Kelly. That means it was a variation on a sound she’d already been recording in—not a complete shift into a different genre.

But it’s important to understand that “R&B” has been a catch-all term for black music since its invention in the late 1940s. It was initially used to describe jump blues and upbeat jazz recordings, then the more energetic, youthful sound of the mid-1950s rhythm & blues, but sometimes also included polished black doo-wop artists. By the 1970s, it had become more of a blanket term—but still mostly used as a generic moniker for black popular music.

In the late 1950s and early 1960s, “soul” had emerged as a descriptor for the kind of gospel-infused R&B Ray Charles launched into the charts. Soul was born of R&B. Soul was originally a distinction given to rhythm & blues filtered through the fervor and progressions of traditional black church music. Over time, “soul” also came to mean everything from the urban sounds of ’60s Sam Cooke and Motown to an ambitious generation of ’70s singer-songwriters who’d added jazz and funk to that original template. In the ’90s, “hip-hop soul” artists were those who brought obvious rap leanings into things; while “neo-soul” artists were also hip-hop-influenced, but more explicitly connected to that ’70s singer-songwriter tradition and eclectic presentation. Presenting “soul” and “R&B” as two completely separate categories ignores that history; for all intents and purposes, soul was originally a kind of R&B—and it more or less still is.

Contemporary R&B was born out of shifts in black popular music via not only the emergence of hip-hop, but genre-breaking black artists like Michael Jackson. Jackson’s Off the Wall is considered by many to be a purer “R&B” album than the record-smashing Thriller that followed it; but both albums feature most of the same songwriters, session musicians and producer in Quincy Jones. Thriller got more play on white radio largely because of a roll-out that was designed to do just that, from releasing the Paul McCartney duet “The Girl Is Mine” as the first single to prominently announcing Eddie Van Halen as guest guitarist on “Beat It.” But aside from that hard-rock workout, there isn’t a lot on Thriller that one can’t find a precursor to on Off The Wall. Once again, “pop” has more to do with how music is marketed and to whom than what it actually sounds like. Michael Jackson becoming “The King of Pop” was deliberate: “pop” is typically a white category, and “R&B” is used to relegate black artists. No “King” wants to be relegated.

Throughout the 2000s, white artists marketed as “pop” worked with songwriters, producers and other collaborators routinely marketed as “R&B.” Full Force are famed R&B hitmakers, and they penned the Backstreet Boys’ 1998 hit “All I Have To Give,” and also worked on ‘N Sync’s debut album. That work with pop acts brought the six-man crew back to chart-topping prominence, but it begged the question: is pop just R&B with a white face? Contemporary R&B of the ’80s, ’90s and ’00s has never been given its due by mainstream critics and press, while hip-hop was culturally elevated as its consumer base became increasingly white male-driven. But R&B was demoted to supporting star as hip-hop was heralded as the important black music of Gen X and Millennials.

A 1999 New York Daily News article on Full Force’s work with these groups reveals how dismissively critics and fans often saw R&B of the 1980s. “Full Force was the ’80s,” begins Denene Millner’s piece. “And like many things from that era—save the ever self-transforming Madonna—the six-member band/production team was, well, forgettable. But now, after years of irrelevance, they’ve managed to re-create themselves in a way no ’80s black R&B group has done before. They’re writing hits for the country’s hottest all-white pop stars—most especially the Backstreet Boys and ‘N Sync.”

The Neptunes also produced major hits for ‘N Sync, as well as solo Justin Timberlake, Britney Spears, All Saints and No Doubt. That production duo rose to prominence via hip-hop and R&B hits, but their sound was their sound regardless of how it was marketed and what artist it was attached to. A Neptunes-produced track for a white artist was typically marketed as pop, not because of any major stylistic shift—but because the artist selling the hit was white. Kelis was one of the most innovative artists of the era, but she was marketed as R&B, which was code for “black”—and “black” meant marginalized by an industry that prefers white faces to sell to pop audiences.

“Pop” isn’t so much a musical genre as it is a cultural distinction. To “go pop” means to have masses of white people suddenly buying your music. “Pop” is a blank slate on which white consumers project whatever sounds are popular at any given moment. The Monkees were “pop” and Debby Boone was “pop” and Celine Dion was “pop” and Jessica Simpson was “pop” but they don’t sound like each other and they aren’t presented as part of the same genre or the same lineage. For the better part of 40 years, “pop” has just been a way to sell the mainstreaming of quiet storm sounds, urban contemporary sounds, dance sounds, hip-hop sounds and, yes, R&B sounds without the racial implications. So Perez Hilton is right: Mariah is a pop star. She’s just a pop star who sings R&B. Because that’s all most contemporary pop really is anyway.