Some may say that Funk is just Funk (which is hard to counter for fusion genres), but there is a difference between well known vocal (Early) Funk aimed at performing and the heavier, instrumental Funk focused on recording, known as Deep Funk. Although this genre already existed in the early seventies, the popularity of Disco pushed a number of artists underground during the eighties. Bass got stronger and breaks became more pronounced. The focus laid slightly less on fast drums and rolls but more on a slower tempo groove, pushing the music forward. Production was very raw and gritty like Southern Soul. Lots and lots of barely known artists brought out their own, more modern approach of their favorite genre, almost always on vinyl (particularly 45rpm singles). Although these records did get pressed, the number of editions was usually meager. These hard-to-find records (hence Rare Groove) were being hunted by Hip-hop, Acid Jazz, and Breakdance DJ’s everywhere (and still are). Rare Groove’s characteristics (heavy beats, instrumental, recording-focused, relatively unknown) make the genre ideal for sampling and extremely popular with Rap and Breakbeats artists.
Starting in the nineties, a new wave of international artists created their own version of Deep Funk, dubbed “Nu-Funk”. Nu Funk uses often Latin or exotic influences and more electronic means to create the music, but otherwise it is very similar to classic Deep Funk.