The hype surrounding Lil Nas X’s “Old Town Road” has been intense, helping the single break the all-time US single week streaming record (143 million).

While Lil Nas X lays down some tidy bars, the real earworm is courtesy of Dutch producer YoungKio’s sample of Trent Reznor’s “34 Ghosts I-IV” for Nine Inch Nails. Reznor has collaborated with rap artists, but it’s usually in the shape of experimental acts like Saul Williams and EL-P.

Yet “Old Town Road” is just the latest in a long line of rap crossover tracks, and while the song may be record breaking, it’s far from the most adventurous musically; only time will tell if it remains influential. Check out the 6 rap crossover tracks that we think set the benchmark.

Run-DMC ft. Aerosmith – “Walk This Way” (1986)

Rock and hip-hop combinations often yield mixed results, but the musical alchemy can be glorious when the stars do align. “Walk This Way” is the granddaddy of crossover songs. Sure, the Aerosmith original was pretty good, if you like that sort of thing, but with Run-D.M.C. rapping over the cover together with Rick Rubin sprinkling stardust in the production studio, pop culture history was made.

The rowdy rock vs. rap music video, directed by Jon Small, contributed to Run-D.M.C.’s version of “Walk This Way” charting higher than the original, Raising Hell achieving triple-platinum album status, and the resuscitation of Aerosmith’s career.

All these achievements are all the more remarkable given Rev. Run and DMC’s reticence towards Rick Rubin’s initial idea of covering the song, and a supposedly frosty relationship between the two bands.

Jungle Brothers – “I’ll House You” (1988)

Two years after “Walk This Way,” the Jungle Brothers (Afrika Baby Bam and Mike Gee) released their debut album Straight out the Jungle. The record kick-started the benevolent Native Tongues movement alongside A Tribe Called Quest and De La Soul, yet it was the euphoric “I’ll House You” that caught fans and critics attention. “House music all night long”, “Say whaaat!?” Mike Gee responds, incredulously.

Produced by house music legend Todd Terry, un-credited on the album, hip-house was already bubbling up in Chicago but Terry turned up all the studio knobs and whistles to make a classic. The producer samples house tropes such as the yelp from Royal House’s “Can You Party” and cowbell from “Optimo” by Liquid Liquid. Straight out the Jungle dawned a new movement and a (micro)genre-defining single all in one album.

Sonic Youth & Cypress Hill - "Love You Mary Jane" (1993)

“Love You Mary Jane” appeared on the 1993 action/crime film Judgment Night. A cult soundtrack of the same name that saw the hippest rock and rap acts of the era join forces. Some of the collaborations appear relatively logical, for example Living Color and Run-D.M.C., or Slayer and Ice-T.

A Sonic Youth and Cypress Hill collaboration doesn’t seem so obvious. With track producer DJ Muggs telling Rolling Stone that metal band Ministry was his first choice for the project and that “It just wasn’t workin’. There was no vibe in the studio [with Sonic Youth].”

Yet Kim Gordon eventually fell upon the hook: her breathy ““Sugar come by and get me high,” B-Real did his shtick, and the rest is stoner rock history.

Massive Attack ft. Mos Def – "I Against I" (2002)

Fast forward nearly a decade and we have another game-changing collaboration from a film soundtrack. Blade II, directed by the auteur Guillermo Del Toro, had a score based on a similar concept to Judgment Night — both albums were released by Immortal Records — with electronic and dance music producers this time teaming up with the finest MCs of the day.

“I Against I” flew under the radar upon release. Given away as a free download via the Massive Attack site. “I Against I” was also overlooked as a single in favor of the Roni Size-produced “Child of the Wild West” (featuring Cypress Hill). Yet it remains a highlight of the album and the rarely explored ground between techno and rap.

Robert Del Naja’s production sounds like icy, space-age techno lifted from a Philip K. Dick novel (never mind a Hollywood movie), while the artist formerly known as Mos Def is in peak form. His zero-sum narrative flawlessly complements Del Naja’s brooding beats.

Necro – "Who’s Ya Daddy" (2005)

In the late 1990s, a white, Jewish, rapper emerged from Brooklyn that made Eminem look like the lead singer from Coldplay. As a teenager, Necro played guitar with a number of underground hardcore metal bands in New York as well as winning a rap demo contest on the highly influential Stretch and Bobbito Radio Show. He has been prolific ever since, but it’s on The Sexorcist where he’s at his most urgent, in particular the brutal “Who’s Ya Daddy.”

A garage rock inspired song, “Who’s Ya Daddy” samples '60s English band The Zombie’s “Time of the Season.” Necro isn’t the only rapper to sample the track, with Eminem, ScHoolboy Q and Post Malone all using it, but he was the first.

Aside from shock value, which has become increasingly reductive, Necro has spent an entire career exploring the darkest niches between hip-hop, death metal and rock, even attempting to create his own ‘Death Rap’ genre. If nothing else, he is a savage curiosity.

Edan – “I See Colors” (2005)

From the same year as Necro’s The Sexorcist, Edan released the gloriously fertile Beauty and the Beat. The album received a rapturous response from critics, with Pitchfork awarding the record an 8.8 and the NME ranking it in its "500 Greatest Albums of All Time" list.

Edan is a true musicologist; sampling mind bogglingly obscure records with a boundless enthusiasm for different genres and production approaches. Lead single “I See Colors" epitomizes this.

The self-anointed ‘Humble Magnificent’ is quick to recognize: "Prince Paul already used this loop." (The Dells' “I Can Sing a Rainbow”) But not as well as this, as references to astrology, early rap-pioneers and food analogies collide in a dizzying display of hallucinogenic hip-hop.

The six songs above represent just a taster of the wide gamut of the rap crossover universe. From the classic rock of “Walk This Way” through to the various stoner, garage, psychedelic rock and metal iterations; not to mention the house and techno crossovers courtesy of the Jungle Brothers, Mos Def and Massive Attack. Hip-hop by its very nature is a sample-based art form that can draw from and add to the most surprising of sources.

Hell, “Old Town Road” might not even be the best example of a rap-country crossover track. There’s the good - Lil Wayne dipped his toes into cowboy territory with "This Is The Carter" (from 2004's Tha Carter) and Mo Thugs Family Feat. Bone Thugs-N-Harmony, "Ghetto Cowboy" from 1998; the meh — Bubba Sparxxx even dedicated a song, "Country Folk" — and the downright saccharine ugly, hello Nelly and Tim McGraw!

For further reading, check out 6 things you didn’t know about Lil Nas X’s “Old Town Road.”