The article says that it started getting used during the late 2000s, but this song seems to use it in the year 2000, and from the usage it doesn’t sound like it’s particularly obscure.
by 1895, perhaps 1847, from low key in some sense relating to deep musical tone or quiet sound; see low (adj.) + key (n.1). Low key in reference to a quiet voice is attested from 1837.
The term is much older. Certainly low-key lighting, for both still and cinematic use is well understood, and goes back at least a century, if not longer.
The key light is the frontal lighting that shows the subject, a low key lighting emphasis the background and not the subject.
Given its very long use in photography and cinema I would suspect that it goes back vastly longer in its current slang meaning as well. I can certainly remember using it many decades before 2000. Minimally, professionals in the photographic and cinema world would have been comfortable using it to mean subtle right from the start.
It is probably suffering from a common habit of young things thinking they invented something new.
I think there is a difference between “Let’s keep it low-key” and “I low-key like that kind of music”. The first one I remember as being around forever, but not the second one. However, the music video I posted seems to be an example of the second one.
Yes the term is old as salt. But the modern way of using it is different than the term posters here are remembering from their youths. I’ve only started noticing it in the early 2010s or so.
That is mentioned in the article. Posters should read that first before replying, as it goes over the modern usage, as an adverb meaning “to some extent.” That’s not how I used it in the 80s and 90a. We’d use it in the sense of “laid back” or “not flashy” as in, “that was a pretty low-key party.” Today they might say “I low-key like Olivia Rodrigo” or something like that. That’s the usage the OP is interested in.
This geezer has never heard nor read of “low-key” used in the way the OP 's article discusses. All that proves is that I’m out of touch, but it also suggests this usage didn’t / hasn’t yet made it too far into mainstream print media.
I live in Chicago, too. You need to either be interacting with younger folk, or watching/reading YouTube/Reddit/TikTok. I see it all the time in YouTube comments for videos that also attract a younger audience. I hear it from my 8-year-old as well.
ISTM part of the confusion lies in that the page linked in the OP seems to address exclusively this particular “newer” usage, without going into how expressions like “the event was kept low-key” or “he took a more low-key tone” were in use since way back in the 20th century.
But that’s what the OP is asking about – the “modern” usage.
I should add, it can also mean something like “secretly” when used as an adverb in the modern way.
ETA: The song referenced in the OP contains this lyric:
“You see me wearin’ baggy jeans
And my fat ten stays on my feet
I never smile when someone’s around
I’m low key stayin hardcore
I’m never listening to anything else
But the hiphop which y’all can’t feel”
Which does sound like one of the modern usages of the word, apparently back in 2000. I definitely have not heard it back then, but I also wasn’t in the US back then. For me, it’s more somewhere in the early 2010s that I first became exposed to usages like this. The earliest “good” (as in same definition and up-voted) citation on Urbandictionary I could find goes back to 2010.
I suspect there’d be less confusion in the thread if the OP had said any of this in the post itself, rather than forcing his cite to do all the work of telling us what he’s talking about.
My kids, especially my oldest, use it in the modern way. I’d wager that that usage is 20 years old or younger. She’s 26, but didn’t start using it until she was a teen.