2000's - Indie Rock / Emo / Nu Metal

2010's - EDM songs with Pop singers and/or rappers on them

2020's - It's too early to say.

I don't follow music much, but I have a guess anyway. It seems like the number and diversity of genres just absolutely exploded since trading .mp3 files became a thing. And with digital stores and YouTube, distribution isn't a hurdle anymore, publishers don't have to pick and choose which albums to release, they can just do 'all' of them.

So there's just no longer one single sound that can define a decade the way it used to be, now people hear hundreds of wildly different bands in a year instead of a few dozen that were hand picked by studios because they had trendy sounds.

2000s, like others have said, was pop-punk, emo, nu metal. 2010s were cloud rappers, mumble rap, and bro country. 2020s I think are seeing a resurgence of pop, though with more aggression (both sonically and lyrically), and progressive subgenres of larger genres, as well as a lean towards inclusivity regarding sexual identity and preference. We won't know until it's over, though. We aren't even to have half-way mark of the 20s yet.

2010 - EDM, also dubstep (brostep) and Drum & Bass become widely popular.
Edit: If you're into Drum & Bass or Trap music, check out these lemmy communities: !drumandbass@lemmy.world and !trap@lemmy.world

Nothing. From my experience the internet has made it trivial to find bands of every style and I have not been able to pin one style to any decade. Even the top 40 hits of each year have been wildly varied compared to previous decades.

2010s into the early 20s had a bit of a folksy thing going for a while with Mumford and sons and some other similar bands, the sea shanty kick a lot of people went on during covid, etc.

Dubstep also happened somewhere around the 2000s-2010s

Early 2000s had some people people were still surfing 3rd wave ska

This is probably just the circles I've been in but folk metal feels like it's been going pretty strong for the last 10 years or so

I also think country has been having a weird moment since around 2000 or so, some of it good, most of it not.

Vaporwave came into existence somewhere and I feel like that's just been kind of hanging around in the background present but largely unnoticed which I think is kind of the point

Not necessarily a genre onto its own, but mashups, remixes, covers, etc. I think have kind of become a surprisingly huge thing.

2000s - The rise and fall of Nu Metal, at least in my country.

2000s had pop punk!

The past 10 years has been dominated by female solo singers

2000s: garage rock revival 2010s: was this the decade when americana began to gain mainstream traction?

I know that 2010's might be rap, but other than that, I'm not sure. I tend to think of those decades as more about the dance, 2000's being the macarena, 2010's being gangnam style, and the 2020's being the Fortnite dance, give or take.

I don't think the 2000s have much of anything. We keep remaking old things.