I'd suggest more torso movement though... like swaying.
Intake of breath raises the head a bit, especially in singing. The hair is driving me crazy tho O.O It was flickering.
Dance moves are nice! There are times when the moves and camera can be too jerky though.
I'm not sure how you do your animation tho....I mostly use Maya when I try to animate so I don't know if other programs are the same. To polish out movement, I make it really slowly in the beginning. This way I have more spaces to smoothen out the movement transitions. When a certain part is finished, I compress the keyframes (each move) to speed it up.
I also try to keep into consideration breathing and balance. People sway left and right when they stand still. A professor told me before that people and animals are never still. Blood keeps pumping, so we keep moving.
Also try to experiment with lights. The first time I tried to render, I always used 1-2 lights. Now I use 6-8 lights depending on what I use to render.
In the Ura-Omote Lovers, I think there was either a light problem or polygon problem.. it caused the black triangle to appear on her left shoulder. Also notices some deformation to the right shoulder. I love how the hair, ribbon and dress moves.
Ura-Omote Lovers and Fragment of Time are my favs here. ;) Keep it up!