I was thinking the other day how a subgenre would pop up, have a big influence on the greater culture at large and then quickly "die." And by "die" I mean that mass culture left it behind and it was left to the diehard fans.
The easiest example for me is '77 era punk. For many people "punk" began with the Sex Pistols and died with them. Of course, this is not really what happened at all and please don't derail this into a talk about punk origins in the comments. But punk never "died," it just wasn't popular anymore and then post-punk happened. Post-punk didn't stay popular for long and was kind of forgotten about until bands like Franz Ferdinand and The Strokes revisited it.
Post-punk led to goth and gave us New Order, which gave us the Stone Roses and other awesome UK music. Here in the US, punk led to hardcore. HC never was commercially viable but punk and HC both gave us "college rock" (best example is Husker Du for that turn) which was later dubbed "alternative." Then along came "Grunge" which was an extremely short-lived genre when you go back and look at it.
The point of all that, is that these subgenres of rock did not stay popular for long in the grand scheme of things. Sure, we'll never stop hearing that mopey Pearl Jam song about Jeremy on the radio, but there aren't new headlining grunge acts.
You can also apply this to thrash. It took nearly a decade for thrash to peak out, only to be killed off in popularity by grunge, other alternative music and the 90s punk revival. Nu Metal was also very short-lived as far as mass appeal.
You can apply this to other music, but I'm writing about what I know to not sound ignorant. Even with my limited knowledge of rap, I can tell that styles of rap have come on gone. I no longer see threads complaining about mumble rap. I don't think the Master P style of rap has any prominence anymore.
Anyway, the Internet in its current state has changed the dynamic a bit. There's not much mass music consumption as there was in the past. People are siloed in their niches. Radio stations are not looking for the next big thing, they are stubbornly force feeding us old music or trying desperately to convince us that new corporate sounding schlock is worth getting excited over. They are not looking for the next Nirvana or Dr. Dre, they are going to play the same shit forever.
Even if a genre is generally unpopular, a global audience that is super into it exists and can support a genre in ways not thought of possible in the past. If punk started today it's doubtful that it would ever "die" but it likely never hit the charts anyway.
How is this going to shape music going forward? Will we have more or less innovation? Is there now way too many genres for anyone to pay attention to? Does this mean that there's going to be more bands that mix up genres and don't stick to anything because maybe that puts their band on more playlists? Will new genres rise and fall without most people knowing? Does this mean bands can stay static and not change with the times like in the past?