Hi Chris
Good, solid photography.
I like your black and white conversions.
Watch out for over-use of 'Dutch Tilt'. I went through a phase of using it (over-using it) on many photos and now only use it for effect every now and then. See -
http://www.pauljones.org/?p=528
Photo 1: On piano
I like what you were shooting for here. I feel the tilt is perhaps a bit too much, but that's just a personal thing.
I wonder what the effect would have been if you had introduced some back-lighting to lift her out of the darkness a touch.
Nice bit of light hitting the piano keys.
Photo 2: Mirror
Beautiful capture of her face in the mirror. Really nice.
Lovely black and white treatment.
It's criminal that you didn't include all of her bum in the shot, though. The bum/knickers would have finished it off nicely.
Photo 3: On piano
I like the closed eyes expression here.
Including the piano keys may have given it more context, but a lovely shot.
Photo 4: Colour
This one doesn't work as well for me as the black and whites.
I find that the vertical crop maybe cuts off too much of her body, for me.
This is all just my own personal opinions, so feel free to disregard.
Thanks for posting. Let's see more from you.