Boom bap is a style of production in hip-hop music. The term "boom bap" is an onomatopoeia for the drum sounds prominent in boom bap. It is usually recognized by an acoustic drum loop/break that is then chopped up and played using a sampler such as the Akai MPC or the SP1200. The term was popularized by the album Return of the Boom Bap by KRS-One.
Boom bap production was associated with producers from New York City in the late 1980s and early 1990s, such as DJ Premier, Pete Rock, KRS-One, Q-tip, Ali Shaheed Muhammad, EPMD, RZA, Marley Marl, Large Professor. The production style was also employed by producers outside of New York City, such as J Dilla in Detroit and People Under The Stairs in Los Angeles.
Although it is still made, boom bap is no longer the dominant style of hip-hop production, remaining somewhat prominent in alternative hip hop but rarely appearing in Top 40 hip hop singles. In recent years the boom bap production style has made a slight comeback through artists such as Joey Bada$$, Pro Era and associated acts.
·Having a "drunken" or "trippy" quality to its rhythm. Most other hip-hop beats has even eighth and sixteenth notes, but many examples of boom-bap are only even at the quarter note level -- the eighth notes may be offbeat.
·Soul music, jazz, R&B and reggae sampling is utilized. This could be said about 90s hip-hop in general though. Boom-bap beats are most often funky.
·Relatively less dense drum loops. Often, a boom-bap measure is just quarter notes (kick-snare-kick-snare). Eighth-notes are less emphasized but are crucial to making the boom-bap sound because they are placed offbeat to create that drunken or trippy quality. However, less dense drums does not mean it's simpler -- it takes craftsmanship to find samples that go well with snare drums.
·Pick-up notes. They tend to be very close to the upbeat of the note it picks up to, especially noticeable in the kick drum. Sometimes the note it picks up to is even substituted completely by the pick-up note.