Courtesy of a link at Christopher Burg's blog, I learned of the existence of the Wagakki Band, which according to Wikipedia "fuse[s] Vocaloid songs with wagakki (traditional Japanese musical instruments) and Western rock". I listened to the song he provided, and found it intriguing: so I tried to learn more about the group. It's relatively new, having only been in existence for three years and produced two albums so far.
The band's Web site is heavy on flash imagery, but doesn't provide much detail. However, there are a number of their music videos on YouTube. For your entertainment, here are two of them. Since I don't speak or understand Japanese, I can't tell you what they're about: but the combination of traditional and electronic instruments, as well as the nasal, wailing Japanese singing, produces a unique musical expression. See what you think.
If anyone can point us to sources with more information about the band, I'd be grateful.