This one is a little bit related to the last ERM. It's also about people trying to push through a message, a self-promotion, in the entirely wrong place. The difference is that here, they're earnestly to make it appear to be pure fact.
Wikipedia's 2 million plus articles and completely free editing aren't the easiest thing to police in the world. There's plenty of examples of people putting up a page about their own obscure little band, or just linking to their myspace page from the article of a bigger band or genre. However, these usually dissapear fairly quickly, as they tend to be fairly straightforward to spot.
For longer-lasting self-promotion, a clever Wikipedia vandal will tap into wikipedia's vast web of genres and post their own genre. Being less obviously based on notoriety, genres are much more difficult to disprove and tend to stay up much longer. And maybe, just maybe, one of them is hiding the next big thing...
The gold standard example of a successful genre placement is the "local scandinavian" (in reality, one group of friends) genre of skweee. Not only has the genre page been up for a year, but they've managed to keep a reference on the page of much more notable genre electro for almost as long! I'm sure I'm not the only one who's discovered Skweee (what a fucking stupid name, btw) this way. It's not bad stuff, and might well stay on Wikipedia as it seems to stand a decent chance to breach noteriety. Ironic - Wikipedia writing music history instead of describing it!
There are a few others that probably stand a smaller chance. Genres with tiny stub pages and few links to them like thizz, birdcore or Brick City club (and that's just from the genres of hip hop page) will probably be edited out eventually unless someone rewrites them better. But they still last longer than those pure band pages!
Finally, another sly way of self-promotion on Wikipedia: this map is prominently located on the hip hop of the United States page and includes at least one genre too obscure to have a Wikipedia article that has stayed up! The "Bamabounce" music that's created by seemingly just one person (the annoyingly named DJ (7)+->) and possibly one of his friends is way obscure (plus it's just bmore, really) but nevertheless it's managed to place itself in a considerably more illustrious circle...
Update: This page of "music genre stubs" (short articles describing music genres, often automatically labelled) is a great source for finding tentatively launched genre labels, trying to get into the mainstream discourse. A few of them will make it (heck, a few of them don't belong there at all, they should have proper length pieces) but many of these labels will inevitably dissapear. Catch them before they're gone!
SEXXY SATURDAY CUMBIA – MARCH
2 days ago