I think the vocaloid music scene is independent in the real sense.
This is the CM of Google Chrome appointed Hatsune Miku,the girl with green long hair.
Miku isn't the character of some animation,but virtual singer developed by Crypton Future Media.
It uses Yamaha Corporation's Vocaloid 2 synthesizing technology.
No sooner had it been released in 2007 than many songs using Miku software were made and uploaded to "Nico Nico Douga"which is Japanese movie sharing site like youtube.
The chain of creation has started by people inspired by the music uploaded.
For example, someone made animation video for a song ,and someone who saw that danced like that.
These works and performances were uploaded mainly to Nico Nico Douga.
Crypton Future Media saw the fever,then made guideline to admit the derivative works using the character within the limits of non-profit and gratis.
I think it's great because it made these free creations possible.
But the phenomenon was sometimes a threat for existing music business.
The most of creations are made for fun not for money but sometimes they are better and more popular than professional works.
They don't hit the chart but number of views shows their popularity.
Now vocaloid can't be ignored anymore and not a few are trying to make money from that.
Some creators turned professional.
Miku's live concerts using hologram were held in recent years.
Performed songs were the most popular among more than 30,000 songs made by various amateur artists.
