Hardcore and punk bands have been experimenting with mixing genres forever, and there are many well-documented instances of this. Ska, hip-hop, jazz, funk, and even drum and bass, have all had their places in the canon of our musical subculture, and with varying degrees of artistic success.
When the '80s became the '90s, there was a brief time when reggae entered our scene. Long before some of this might be considered cultural appropriation (notably, with specific lyrical references to Rastafarianism and hilarious attempts at singing in Jamaican Creole), it’s pretty unclear how or why this sudden interest in reggae appeared.
Given the time period, as hardcore’s second wave died out myriad bands took the route of experimentation, traversing crossover, hard rock, funk and the not-yet-coined post-hardcore. This was of course before ska-core was even a blip on the horizon (save for Operation Ivy, who was just starting to make small waves and perhaps a single track by Murphy’s Law).
Needless to say, the reggae injection was a bit more subdued. Maybe it had to do with the Bad Brains becoming more popular and influential, or perhaps HR’s emerging solo project had a say. It could have had something to do with the rising popularity of mixed-genre bands such as Fishbone and 24-7 Spyz, their nods to Rastafarianism being readily digested by suburban alternakids nationwide.
Either way, as the musical rules were relaxed we saw a small handful of hardcore bands who flirted with reggae parts, a short-lived union that has likely been long-forgotten.
Underdog, "Mass Movement"
Richie Birkenhead's haunting vocals are a good fit for this reggae-infused intro, which gets reintroduced at the end of the song. Underdog pulled off the merger pretty well, maybe offering a sneak peak of what Richie was capable of outside of traditional hardcore.
Underdog, "Without Fear"
This is probably the most notable example, as this song starts of with reggae and morphs into straight up dub, completely ignoring any NYHC sensibility whatsoever.
No Future?, "Where Do We Go?"
Considered part of the New Jersey shore-core scene, these guys released a demo in 1989 and a 7” in 1991 and then split up, presumably for college. The music is catchy and changes unexpectedly from catchy posi-core to a sung reggae part in "Where Do We Go?"
Hogan’s Heroes, "Dread or Alive"
Hogan's Heroes vocalist Skip Hoefling had one of the best screams in punk rock at this time, but he starts off the aptly named Dread or Alive with just over a minute of pure reggae before entering the realm of blistering, fast music for which the band was best known.
False Justice, "We Must Unite"
As far as I know, False Justice was little known outside of southeast New Jersey during their existence in the late '80s. They released two awesome demos of ripping hardcore with a slight thrash influence. Their 1989 demo included the song "We Must Unite," featuring two reggae parts (at both the beginning and end of the song) accented by a cringeworthy faux Jamaican accent.