Traditional Japanese instruments/singing backed by rocking bass and percussion. Have I mentioned I love this sort of thing? Well, I do. Audio quality is ace. (Not so much the live, but this is one of the few lives I've listened to that weren't recorded like ass):
These guys are so cool. I'm ordering all their stuff.
A lot of their songs are rearrangements of those from Vocaloid composers. Now... just saying. I hate Vocaloid voices. Like synth strings, they sound terrible. Especially attempts at vibrato or trilling. WTF is that!
But it's about the composition, right? Vocaloid is great for producers who otherwise don't have access to those resources. Then live performers like Wagakki can swoop in and take it home. So you could say Vocaloid is doing some good.