I've been messing with finger drumming with midi controllers, and one thing I've noticed time after time is how prevalent alternating kick/snare. Especially Kick on Beats 1 and 3, and Snare on Beats 2 and 4.
Especially in regards to hip hop and most beats I hear on youtube videos. They call it "boom bap" in hip hop, but I think it happened before boom bap.
So did it originate from hip hop or maybe rock? Is this the most basic rhythm or are there others as popular?
Yes, typically what you're hearing referred to as "boom bap" is what's called (to normal musicians) a breakbeat -- which differs from a steady or "four-on-the-floor" beat, in the sense that the lower percussive element (kick) is on a broken beat.
So you have four distinctive rhythmic elements in play. As far as I know, all of these have roots in rock/blues/jazz, and probably older.
If you cross-reference these styles, you get a 2x2 grid of possibilities that influence most popular rock/pop music styles:
Worth noting, it's not uncommon to see these styles mixed within the same song even, so it's not like these are hard guidelines, but just explaining how these rhythmic elements relate to one another.
Great question!
I think it's so prevalent because it is the smallest and simplest form of alternating sequence we can fit in the most common rhythm structures. The accentuated 2nd and 4th beats comes from the heavy disco and soul influence that carved early electronic dance music, which in turn influenced all the scenes related to sequencers, sampling, and synthesizers. These patterns are so prevalent that some styles deliberately avoid them in favor of syncopation, polyrhythms, and seeking new rhythm palettes.
It's not normally an alternation though; both kick and snare accentuate the beats 2 and 4. Sometimes the snare fills so much of the spectrum and is so loud, that the kick bellow it is hard to hear. Because of this, some producers started using snares that have a low-end, and not using them at the same time as the kick. But that's still not much of an alternation, since the function of the kick is still being covered.
The actual alternation (snare that doesn't also fills the function of a kick) comes from wanting to give a slower feel, without slowing the actual bpm down. You are still accentuating every beat, so the flow is very similar, but the feel is slower.
So, the alternation comes from wanting to half the feel, without halving the speed (if that makes sense), the pattern comes from being the smallest and simplest manifestation of alternation (same reason why we can find it in many other genres, just sometimes the accentuated beats are 1 and 3) and accentuating beats 2 and 4 comes from the early disco and soul influences of electronic music.
Drums, which are also known as membraphone are a part and parcel of the percussion family. Percussion are as old as mankind and have their roots in Africa (the cradle of mankind) even up to this very day they are still being played by the natives and the shamans. The moment when the first caveman could hit objects against each other to produce sound, be it hollow bones and coconut shells, percussive rhythm was born. When mankind evolved and acquired better tools, he then discovered that he could actually put a membrane over a hollow object to create an improved, more amplified and rounded sound - that's the first drum. Also note that, drums were used for various purposes, from long range communication to shamanic healing and spiritual invocations purposes, from dance to scaring away predators (today in South Africa, Botswana, Zimbabwe, Zambia, Namibia, Kenya farmers still use drums to chase away elephants from their farms).
Through the process of evolution, man also discovered that different drum sizes produce different sounds. This difference in pitch and tonality, is what mankind used in his long distance communications for "call and response" - which is basically a more organized and structured rhythm which is easier to understand. This drums and percussion were usually played by different people at the same time, hence the need to play and pause (talk and listen to what others are saying) - the Talking Drum.
That covers the prehistory part of the drum, now let's us focus on a drum as a modern day musical instrument. Fast forward to the 19th & 20th century, drums from the matches band were combined and arranged in such a way that they could be played simultaneously by one individual as opposed to a group of people. This did not throw away the ancient elements of, "call and response", "high and low", "light and dark", "loud and soft", etc this is exactly what the high snare and low kick drum are trying to emphasize when played in alternating manner to achieve contrast and rhythm.
We should also be cognizant of the fact that music is an art and like all arts it encompasses all of the art principles such as balance, emphasis, harmony, movement, pattern, proportion, repetition, rhythm, unity, and variety. Western music tends to adopt rhythms that are based on 4/4 time, which logically leaves us with either a kick or snare drum falling alternately on one of those beats. Other cultures have different time signatures and rhythms that they play on such as the Sangoma drumbeats in Southern Africa which tend to be polyrhythmic in nature and not straight ahead like its western counterparts.
To answer your question, if the snare and the kick were to be played in unison all the time, they wouldn't be able to create variety of contrasting rhythms, hence alternation is necessary. You can try it for yourself.
