Did you know the song "Old Town Road" is based on a Nine Inch Nails track? It's true. The recent hit from rapper Lil Nas X that juxtaposes traditional country music trappings against the thrust of modern hip-hop — and has taken the Billboard charts for a surprising spin in the process — is built on a sample of "34 Ghosts IV."

The excerpt, taken from the instrumental entry among the many others found on Nine Inch Nails' expansive 2008 set, Ghosts I-IV, can be heard at the tail end of that album's second disc. A plucky-sounding segue of acoustic strings that starts the song is what lends "Old Town Road" its roots. Listen below.

But the sample Lil Nas X used for his breakthrough seems to be the least of the rapper's worries. While it put Trent Reznor and his Nine Inch Nails bandmate Atticus Ross at the top of the charts for the first time, as The Washington Post noted, it's the cultural blend within "Old Town Road" that's shaken up the music world.

All the same, country rap (or country trap) isn't a wholly new genre. In fact, Lil Nas himself pointed to Young Thug as its pioneer. Still, that didn't stop Billboard from removing "Old Town Road" from its Hot Country Songs chart after it decided the tune didn't "embrace enough elements of today’s country music."

Some country artists seemed to take issue with that. Billy Ray Cyrus almost immediately appeared on a remix of the song, and Keith Urban offered his own cover of "Old Town Road." Below, hear the genesis of the hit song.