I have a pet theory: the musical landscape was irrevocably altered in 2005, and since then no new scene has managed to get "Big". I appreciate that it's a controversial comment to make, and that it also happens to be around the time science says I stop listening to new music, so I want to make it clear that I'm not saying good new music stopped being made then (because you can find awesome new music everywhere). I'm simply saying that "Big" slowed down as being possibly for new acts and scenes, at least in the context of what had happened before. And why am I saying 2005? Because that was the year that YouTube landed, marking it as the year that the shared cultural youth experience (one of the most vital things for new things to become Big by) finally got a nail in the head and that scarcity in youth culture stopped being a thing.
Back in the day when the internet was just this weird thing that either hadn't been invented by computer visionaries, was a wild idea of computer science theorists, or was that strange thing the computer students swore they weren't using to look at porn with, there was a high cost of entry into any youth culture, driven by scarcity of the resources relating to that culture. For example, if you wanted to listen to music you had to go and buy the record, or at the very least the tapes to copy it from someone who had bought the record, and you had to buy the means to play that record, But even if you had that record you were limited on where you could play it and you were limited by possibly not even knowing that the record existed or how to contact the people who sold the record. Similarly if you wanted to join a scene you had to spend a large amount of time finding out that the scene existed, where it was, and then you would have to go along to it with no real clue what the culture was like and with the likelihood of sticking out like a sore thumb. If you then wanted to join that culture you would have to invest a considerable amount of funds and effort on buying the uniform of that scene, mostly due to the small number of places actually selling the clothing in question. To put it bluntly: it was a total arse, and because it was a total arse a lot of people didn't move that far outside of their youth scene, even before the tribal violence and rejection fears of the times.
Additionally there were very few media outlets at all for youth music of any kind, let alone whatever scene you may have happened to have been into. On the telly there was Top Of The Pops, and at any given time one or possibly two other music programs (including "Youth TV", which doesn't really count as that has always been terrible) which generally compressed the whole world of music into one show so your rockers and your indie kids and your ravers would all be watching the same show, and 'booo'ing and 'yayyy'ing along like football fans because they all had a lot of stuff that you didn't really like but were willing to watch through for the one or two acts that you did. But even then you would be more likely watching because it was an act from the scene you liked rather than a bad you actually raved on about, with you watching to represent and go "more of this kind of thing please!". This is why The Stone Roses and The Happy Mondays on the same Top Of The Pops was heralded as the triumph of Madchester when they sound like two difference scenes, why Blur vs Oasis was the battle of Britpop rather than retro-pop vs indie-rock, why Rage Against The Machine got big with the rave party kids via The Word and why everyone with a leather jacket I knew watched Slipknot literally destroy the cameras on TGI Friday (even though half of them couldn't stand them). Yes, from the mid 90's if you had access to the mysterious "cable TV) you could watch MTV but that basically meant "20 hours of Radio One a day, with one or two specialist genre shows a night", so if you're scene wasn't flavor of the month then you still had the bottleneck happening where everyone on your scene was watching the same thing.
Now, whilst this may all sound like a pain (it was) those bottlenecks were also very useful because it gave "Bigness" and avoided the cultural balkanisation and scene hopping that is now happening (two contradictory but linked concepts). Because you had a lot of people knowing the same songs (regardless of if it was their thing) the songs could get "big" and get a decent floor going in the club, because you were listening to a lot of music you would never think of listening to a band could find an listeners from a wider audience, because niches were part of a larger overall scene you had more people turning up to broad interest events (well, at least outside of London) so there was more crossover, and because you had to go an engage in a scene to discover things you actually had to get out there and partake of it. From my personal prospective this gave us things like the genre spanning Llollapalooza and leather jackets turning up at raves because The Prodigy had thrown in some guitars and the goths had dug a few Ministry Albums,(then again it also gave us the ubiquitous "Crap Thrash Hour" at the start of every rock club so it may not of all been good). New sounds, new scenes, new tastes could gain traction due to all the reasons listed above.
Then 2005 happened, and Youtube removed the first bottle neck of scarcity. Very rapidly any music you wanted to hear would be accessible to you in minutes, your very own Top Of The Pops playing just what you want whenever you want it. So people ended up listening to just what they wanted, because if you just wanted to listen to hardbag or pornogrind you could do, all day if wanted. You could go as niche as you want and never have to touch anything else. Then MP3 players and broadband became mainstream and took down the second bottleneck, meaning that you could download a bands discography in less time than it would previously of taken to find their single in a shop and you could carry it with you everywhere you wanted with no compromise of availability. Then eBay removed the bottleneck of stylistic scarcity, by making all the clothing available. You didn't have to live near or travel to that one specific store that sold the clothing you wanted, you could sit at home and have 5 stores come to you (and at competitive prices!). All of this was aided by Google having taken down the final bottleneck of knowledge scarcity, so if you wanted to know anything about a scene, from what was happening where to where you could hire a venue to how to spread the word to what was trendy and wearable, you could get it in a couple of minutes.
This was, and will continue to be, mostly awesome. New things to listen to, new places to go, new sounds to hear.
But not all of it is that great, as with the removal of scarcity meant there was no underground for this to dwell in for all that long before they go prematurely big. Or, at the very least, latched onto an chewed through by the novelty hungry machine that was the media. As more and more obscure things came into sight they were all now given their moment in the sun, but often before they could organically grow enough of a following to survive that moment or capitalize on it. Scenes didn't have enough time to become actually big before being pronounced the Next Big Thing and then tossed aside as the long queue of Next Big Things was worked through as rapidly as possible. Things also haven't been helped by the increased discover-ability to the listening public has come along an increased dispensability, as it too goes through a thirsty journey towards novelty and freshness. It is perfectly possible to hear about a new scene on the Monday, have listened to the music on the Tuesday, to have sourced all the fashions on the Wednesday, and know about all the events on the Thursday. Weather someone will then actually go to the event on the Friday is up for debate, as they could easily have moved onto the next thing before then. Scene-hopping and a cultural flatness brought on by observing rather than engaging is developing, you don't even have to go to the shows any longer as you can see it through someone else’s phone video so how can a new scene maintain the excitement needed to become "big" when all of it's mystique is gone at the very first whiff of discovery?
Instead of bigness we have, in most cases, an outbreak of smallness. Niches and specific scenes are totally possible because you can find enough people to keep them going, which is a great thing in many ways but it also leads to the balkanisation that was described above and a staleness that people don't seem to quite get. For example I recently had a friend make the very reasonable and true comment that nothing new had happened in Classic Metal for years now, but I had to point out that that was because all the things that could happen with it had happened about 20 years ago with Nu Metal. With any kind of music its the simple case that if you're going to have a genre described by standing still and a scene made up of people who want a very specific thing it can't evolve or significantly grow because it's whole reason to exist is it's constraints, it's like looking at Baroque and going "well I like it but can we throw in some synths and blastbeats?" The availability of the niche scene has created its own bottleneck where things can't evolve without having to exit the scene, and because there isn't as much group experience available it's not by gathering more people around it but by going and creating it's whole own new scene.
The fact that hardly any new acts that could authentically be described as "underground" are making it into the charts (even the previously awesome 40 to 20 region) is testament to this by itself, with the aging of the headline acts at underground events giving further fuel to it. And it's only going to get worse, as the money is falling out of music so bands and events have less ability to hang around that long and more intensive to find and focus on a specific market. The removal of the bottlenecks has leveled the playing fields, it's just that it appears to have done it by driving things down rather than bringing everyone up. This is why, more than ever, it's important to get out there and represent not just your particular scene but the broad umbrella scene that it came from, to help and keep everyone afloat. Plus, you never know: you might hear something you like but never thought of listening to before.