Mid-school hip hop refers to the first wave of Hardcore Hip Hop, a bridging era between Disco Rap (old school hip hop) and the later sample-based Boom Bap (new school hip hop). It was pioneered by producer Larry Smith and Run-D.M.C. with their debut single "It's Like That / Sucker M.C.'s (Krush-Groove 1)". The genre features stripped-down, hard-hitting drum beats courtesy of drum machines like the Oberheim DMX and Roland TR-808, creating a heavy backdrop for the rapper to provide a more "in your face" delivery. Song lengths are also much shorter compared to disco rap and don't have the jam-like/party approach that this previous style had.

Following Run-D.M.C.'s success, mid-school hip hop became the dominant sound in Hip Hop from the years 1984 to 1986. Aside from Run-D.M.C., another landmark album was LL Cool J's Radio, produced by Rick Rubin expanding on the sound that Larry Smith had created prior. In 1986 hip hop exploded in the mainstream with multi-platinum records Raising Hell and Beastie Boys' Licensed to Ill, both also produced by Rubin.

Mid-school hip hop is very much defined by its distinctive minimalist drum machine sound or with beatboxing imitating the drum machine sound. While disco rap featured replayed disco breaks courtesy of a band or stitched up together with turntables, mid-school hip hop rarely features any samples and the music is created originally with the drum machines, synthesizers and record scratches. The release of the SP-12 sampler in 1986 and more importantly the SP-1200 in August 1987 moved hardcore hip hop into the new direction of boom bap, featuring a more sampled-based sound based around Funk samples from such artists as James Brown and Sly & The Family Stone.