AILSA CHANG, HOST:
All right. Now we're going to pause to ask what seems like a simple question - is this a country song?
(SOUNDBITE OF SONG, "OLD TOWN ROAD")
LIL NAS X: (Singing) I got the horses in the back. Horse tack is attached. Hat is matte black, got the boots that's black to match.
AUDIE CORNISH, HOST:
That's "Old Town Road" by the artist Lil Nas Ex, and it sparked a controversy in the music industry over the definition of country music and whether it can incorporate new sounds.
ELIAS LEIGHT: Sort of this amazing, glorious mishmash.
CORNISH: Elias Leight is a reporter for Rolling Stone magazine.
LEIGHT: There's like some guitar strumming and a banjo part, rural imagery that you might find in a country song. And then Lil Nas X sing-raps these lyrics in a sort of drawl.
CHANG: All on top of a beat most associated with trap music. Lil Nas X released the song on SoundCloud in December. It immediately went viral. Within a few months, "Old Town Road" made it onto Billboard's country charts.
LEIGHT: It debuted at No. 19. So when they considered it a country song, it was one of the 20 most popular country songs in the country.
CORNISH: But they didn't consider it a country song for long. This week, Billboard announced it had removed it from the country charts, saying it didn't embrace enough of the genre's elements.
BRIANA YOUNGER: When it was removed from the Billboard country charts, I was not surprised at all (laughter).
CORNISH: Briana Younger is a music editor at The New Yorker.
YOUNGER: Country music, you know, it's an exclusive club, right? They very much want to protect their sonic territory, if you will.
CORNISH: Younger points out that country music has begun to incorporate rap and hip-hop, but it's often by artists already established in the genre like Jason Aldean, who's begun to rap on some songs.
(SOUNDBITE OF SONG, "DIRT ROAD ANTHEM")
JASON ALDEAN: (Rapping) I sit back and think about them good old days, the way we were raised and our southern ways. And we like cornbread and biscuits. And if it's broke around here, we fix it.
YOUNGER: It seems like the door swings one way. People want to dabble in hip-hop and R&B and still be embraced by their home base. But then when black people want to slip out of hip-hop and R&B, they're not as welcome, they're not as embraced.
CORNISH: She says the bigger question here is who gets to decide. On this case, Billboard decided.
HANNAH KARP: We have a charts team. And within that team, we have a lot of different people vetting decisions.
CORNISH: Hannah Karp is the editorial director of Billboard Media Group. She says they made the decision based on the song's musical composition.
KARP: The song does incorporate country imagery and lyrics, but the beat of the song is primarily a trap beat.
CORNISH: Country or not, Lil Nas X is having his moment in the sun. Last week, he signed to Columbia Records. And yesterday, "Old Town Road" was the most streamed song on Spotify in the U.S.
(SOUNDBITE OF SONG, "OLD TOWN ROAD")
LIL NAS X: (Singing) Yeah, I'm going to take my horse to the Old Town Road. I'm going to ride till I can't no more. Transcript provided by NPR, Copyright NPR.