In terms of music, Vocaloids serve as a consistent and accessible tool for creating vocals. The Vocaloid music production community on Nico Nico Douga is enormous and was driven by amateur composers, producers, and songwriters. As song creation became more and more elaborate, the need for instrumentalists grew and they got involved. The videos became more elaborate as well, and people like illustrators and animators got involved in this as well. In a weird way, it also got amateur singers on Nico Nico Douga recognized as well, when they started to cover Vocaloid songs.
Each of these communities is thriving on the Japanese internet today. I say 'was', because today, the community and audience has grown such that a lot of these people have now shifted over to professional production and are selling albums and stuff. So the
real success behind the Vocaloid music scene are all the amateur musicians and other creative people who have a shot at getting their work out.
The most obvious example is that of supercell, who made some wildly popular Vocaloid songs before they went pro and collaborated with nagi, a Nico Nico Douga singer that became big by covering supercell's Vocaloid songs.
Not every Vocaloid producer who goes pro ditches Vocaloids. A lot of them mix in Vocaloid and real vocals in their albums, like in DECO*27's second album, Aimai Elegy, where a lot of his songs are covered by marina.
It's kind of timely, because one of the newer Vocaloid artists, wowaka, is releasing his first commercial album, Unhappy Refrain, today, which consists largely of songs he's uploaded to Nico Nico Douga before.
Anyway, here are a bunch of crossfades for Vocaloid albums:
DECO*27 - 愛迷エレジーwowaka - アンハッピーリフレインハチ - OFFICIAL ORANGE40mP - コタエアワセbuzzG - Symphonysasakure.UK - プロトタイプKeep in mind that these are only album crossfades. A lot of the songs on these albums are actually available on Nico Nico Douga, along with full-blown video.
Oh, and I've written in some depth about some Vocaloid producers (with a ton of links to the videos for some of their more notable songs) before in a
previous thread, but that thread died due to lack of interest.