history lesson
What, you mean this has been going on since 2013???
Precedents
In many ways mumble rap is a return to Jamaica’s penchant for vocal novelty, gimmickry, melody and phonetic Dada that was abandoned when Jamaican toasting became US rapping.
So Fatman’s use of “bo”, “bim”, “oink” and “ribbit” are actually quite similar to ad-libs in mumble rap.
Similarly mumble rap’s more extreme vocal buccaneering is closer to something like major mackerel’s squawks than it is to the conversational naturalism we tend to associate with US rap.
Old dirty bastard also deserves a mention given his vocal delivery and crazed drug-fiend persona chime with mumble rap.
lil jon re-popularised call and response rap ultimately kicking off a trend of cantonised rap. mumble rap is in a sense the attempt to rhythmically reconcile the sophistication of ‘flow’, while avoiding it’s rhythmic contiguity.
Proto-mumble rap
I point to Lil Wayne’s ‘lollipop’ as proto-mumble rap with its use of auto-tune, it’s phonetic playfulness (‘hair’ becomes ‘her’, ‘love’ becomes ‘loov’) and you could even say the choppage of ‘l-l-like a lollipop’ is an incredibly crude preempting of the todd edwards-flows that would emerge in the mumble rap era.
chief keef is another important figure due to his promenenant ad-lib centrism. the use of ad-libs that became a fundamental component in mumble rap’s new rhtyhmic language.
i’d also point to wacka as an ealry exponent of more fragmented flows that were more sophisticated from mere call and response
future’s ‘tony montanna’ is widely pointed to as pioneering mumble rap due to its slurred delivery, but this is an incredibly reductionist understanding of what mumble rap actually is. future’s also important for using auto-tune subtly, in a less overtly melodic way
young thug and to a lesser degree rich homie quan popularised playing around with vocal delivery; doing silly voices, making silly sounds and having unstable pitches that aren’t conversational or melodic. crowley has an incredible in-depth knowledge of of the future swag lineage this belongs to.
migos popularised the use of staccato triplets with ‘versace’. it is also an example of a latent rhythmic aesthetic that they’d fully crystallise a few years later.
Post-‘Monster' Mumble Rap
in the middle of the 2010’s future released a trio of mixtapes that signified maturity; ‘monster’, ’56 nights’ and ‘beast mode'. the first was a concept album and they all dealt with more lofty themes such as divorce, drug addiction, etc.
https://www.youtube.com/watch?v=MDIRKOzIn8I
after that you see mumble rappers transform from being rather inane and internety to producing proper music:
from this:
https://www.youtube.com/watch?v=ovA6iPznvzw
https://www.youtube.com/watch?v=aHT1EDXtxws
to this:
https://www.youtube.com/watch?v=Qg9ZxQKSDuw
https://www.youtube.com/watch?v=Hm1YFszJWbQ