"Duke Ellington said that there's two kinds of music: good and bad."

Helmet frontman Page Hamilton is citing the jazz legend while discussing the Judgment Night soundtrack and its impact. Judgment Night was released on Sept. 14, 1993 and each song featured a collaboration between a hip-hop artist and a rock band. Helmet's collaboration with House of Pain, "Just Another Victim," was the album's lead track. The idea of crossing genre lines to work with a hip-hop group didn't give him any pause.

"When the idea to work with House of Pain was presented to us, I said, 'That sounds like fun,'" Hamilton recalls. "I liked hip-hop, [former drummer] John [Stanier] turned me on to the Pharcyde. I liked House of Pain. 'You guys are really good at what you do, we're really good at what we do, let's do something interesting together.'"

Rock/hip-hop hybrids were not new by '93: Run-D.M.C. had a huge hit with their 1986 cover of Aerosmith's "Walk This Way," featuring Steven Tyler and Joe Perry. In the music video, the hip-hop trio and the Toxic Twins are separated by a wall, each competing to be the louder combo. Finally, Tyler bursts through the wall with his mic stand; when the two sides come face to face, they don't seem to know what to make of each other. Later, Run-D.M.C. bum rush the stage at an Aerosmith concert, and Tyler looks annoyed (of course, what lead singer wants to share the mic?). It ends happily, with Tyler, Perry, Run and D.M.C. rocking out together (the late Jam Master Jay is in the background on the turntables). The two groups became friends; Aerosmith and Run-D.M.C. reunited for a show-stopping performance with Kid Rock at the 1999 MTV Video Music Awards. In 2002, all three acts toured together.

In retrospect, the "Walk This Way" music video's plotline came true: it kicked off a friendship between two bands that didn't seem to have much in common. The video also serves as a metaphor for rock and hip-hop acts working together and being influenced by each other.

Just a few years later, in 1991, Anthrax and Public Enemy collaborated on an update of P.E.'s "Bring the Noise." The video starts with both bands onstage together in front of a mixed crowd. No contrived introductions were needed: Chuck D. dropped Anthrax's name in the original "Bring the Noise," and Scott Ian was often photographed wearing Public Enemy t-shirts (and probably was turning on lots of metal fans to their music just by that endorsement, even before they released the collaborative track).

"Bring the Noise" is where Judgment Night takes its cue from. Rock and hip-hop artists were very familiar with each other and wanted to collaborate.

"We were in the studio together twice," Hamilton remembers of the "Just Another Victim" sessions. "I had this great riff, I was saving it for a Helmet song, but [figured] 'Let's use it!' The song came together quickly, it had to, we were just in the studio for an afternoon. The chorus in the Helmet part of the song is just increasing rhythmic activity, it's not 'Arrangement 101.' Erik [Schrody, aka Everlast, House of Pain's lead MC] and I talked about lyrics. I'd been mulling over the idea of people feeling victimized and not assuming responsibility, and he liked that idea."

"I did the vocals in their studio in California. They were in a much nicer, high-tech studio than ours - we were working in [producer] Wharton Tiers' basement, where we recorded [1990's] Strap It On and [1992's] Meantime, and also [2006's] Monochrome a few years ago. Once we finished our half of the song, we gave it to them, they slowed the riff down. then Leors [House of Pain's DJ Lethal] did the DJ stuff. It was fun."

The collaboration led to another unlikely meeting. "They had a bag of weed in the studio [in L.A.], bigger than my body," recalled Hamilton. "I was friends with Timothy Leary, and he had a party for Helmet and we took them and Cypress Hill, and they got everybody incredibly baked."

Speaking of Cypress Hill (whose album, Elephants on Acid, is due out September 28), they had two collaborations on the album: "The Real Thing" with Pearl Jam and "I Love You Mary Jane" with Sonic Youth. At that point, they were so popular, particularly among the rock crowd, the entire album could have comprised of Cypress Hill hookups. Of all the hip-hop groups, they seemed to be the ones that had the best understanding of the rock audience.  When they released the video for "Insane in the Membrane," their first single from their second album, 1993's Black Sunday, it had psychedelic effects that surely resonated with fans of '60s rock bands, and the video saw them performing in front of a stage filled with stage divers.

Cypress Hill's Senen Reyes (aka Sen Dog) says, "We always listened to classic rock, punk rock, stuff like that, even '80s metal." He recalls the first time a mosh pit broke out during one of their performances: "It was at Drop in the Park with Pearl Jam in Seattle, in 1992. We came on and all of this outrageous activity was going on in front of the stage. The kids broke down the barricade, and they stopped our show, four songs in!"

He recalls that the Pearl Jam guys sent them the track for "The Real Thing." "I thought we sounded really good with them," he explains. The Sonic Youth track was one of the only laid back tracks on the album (the others being De La Soul and Teenage Fanclub's "Fallin'" and Del the Funky Homosapien and Dinosaur Jr.'s "Missing Link"). But "I Love You Mary Jane," about a real-life pot dealer named "Sugar," was certainly in character with many of Cypress' other songs.

While the movie -- which starred Emilio Estevez, Cuba Gooding, Jr., Denis Leary, Jeremy Piven and Everlast -- didn't make much of an impact, the soundtrack, produced by Happy Walters, who managed Cypress Hill and House of Pain, certainly did.

Jose Mangin, Director of Rock Programming and On-Air Host for SiriusXM, says, "I had never heard anything like this album, and it came out at the perfect time when hip-hop fans and metal fans were finally starting to come together. I still love it! Hearing Slayer and Ice-T, and Cypress Hill with Sonic Youth was incredible." He notes that the Slayer/Ice-T collaboration, "Disorder" (which was actually a medley of songs by punk rock band the Exploited, "War," "UK '82" and "Disorder") still gets a decent amount of airtime on his Liquid Metal channel, as does "Just Another Victim," the title track and Faith No More and Boo-Yaa T.R.I.B.E.'s "Another Body Murdered."

Zeena Koda is the Head of Urban Digital Marketing at Atlantic Records, but also hosts a metal radio show on Gimme Radio called "Got That Attitude," recalls, "As someone who grew up religiously listening to rap and rock, I loved it. I remember being a kid and listening to this record, walking through the hood and feeling like 'This is my shit.' This was a very experimental time in the industry for marrying the kings of each of these scenes together. It was inevitable that rap-rock would become mainstream; this was the beginning of an exploration by major labels. This was one of the first times I heard both so seamlessly connected."

Carmen Mark DiGiacomo -- also known as "Squiggy," Loudwire's "Gear Factor" host, adds, "It was this colliding of the worlds, and all of a sudden, there were people in basketball jerseys playing metal. To me, it was heaven sent. It was sent from the gods for somebody like me: when I was listening to it, I finally didn’t feel out of place. I felt like somebody else was speaking my language, and it kind of let me feel like it was OK to be who I was, the kid with the Motley Crue hat on, breakdancing. So it validated me to be the person I was."

Josh Bernstein, Townsquare Media's Director of Live Events and Loudwire contributor, notes that the Judgment Night collaborations had a credibility to rock fans: "It didn’t seem manufactured; it didn't seem like some label executive was saying, 'Make it one part hip-hop, one part metal.' I honestly believed whether it was true or not, that Onyx and Biohazard hung out together on Flatbush Avenue or something. It did feel, at the time, very authentic."

DiGiacomo says that the album's impact was obvious, just a few years later. "I think it solidified and really gave birth to what was gonna become nu-metal, and I unapologetically love nu-metal. For a lot of us that were always in between these two genres, nu metal combined those worlds, for better or for worse. I know there are people that love nu-metal; there are people that hate it, but it spoke to people that look like me, people who love hip-hop, and love metal."

Hamilton adds, "I remember getting interviewed about it back then: 'What is this rap and rock thing?' A couple of years later, Limp Bizkit and Linkin Park and all these bands are selling millions of records."

Sen Dog states, "You saw a lot of rock/hip-hop bands were coming out just a few years later, Linkin Park, Limp Bizkit, Korn, Papa Roach. All of those bands were prodigies of that album. I love the fact that we were part of that."

"The impact of that soundtrack is still being felt today," Mangin says. "It really set the stage for like-minded souls who loved metal and hip-hop to pursue their own style, like Korn, Limp Bizkit, and later Linkin Park. Maybe something like this should come out again, today. I think our metal world should be looking to invite more fans to our party, and vice versa." A good example that some metal bands might want to take would be that of Papa Roach -- a band who certainly took notice of the Judgment Night soundtrack -- who collaborated with a pop singer, Skylar Grey, and electronic music act EMRSV for a remix of  "Periscope." That move resulted in getting them on Spotify playlists that they would never have gotten to on their own, resulting in new fans.

Koda adds, "In some ways, the music scene of today has pulled from that era, erasing hard genre lines. These days, it’s common to hear collaborations; festivals like Rolling Loud and Afro-Punk have changed the way we view the convergence of both worlds. This soundtrack started that fire."

At the time, it seemed that the rock audience took notice immediately, while the hip-hop community saw it as a curiosity. Del The Funky Homosapien even told Rolling Stone, “It’s cool, but it’s some alternative shit. I doubt that it’s the future of rap." Ironically, Del's most well-known song is probably "Clint Eastwood," a collaboration with the Gorillaz, a band led by Damon Albarn, the frontman of the British indie band Blur.

But today, as our sister publication XXL recently pointed out, "Hip-Hop's New Generation Has A Real Obsession With Rock," citing artists like Lil Uzi Vert, Post Malone (who recently jammed with Aerosmith on this year's MTV Video Music Awards) and the late XXXTentacion and the late Lil Peep all cited rock artists as major influences. Additionally, Princess Nokia appears in ads for her A Girl Called Red album proudly wearing a Slipknot shirt and giving the finger to the camera. Machine Gun Kelly -- who is playing Tommy Lee in the upcoming Motley Crue biopic -- has covered Linkin Park. A couple of years back, Travis Scott posed for GQ in a vintage Slayer t-shirt.

Sen Dog says of rock's influence on current hip-hop artists, "It took a while for it to surface. A lot of my hip-hop buddies, they love Korn's music and Jonathan Davis' lyrics. Rage Against the Machine had that effect too. It definitely made an impact, it just took another generation."

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