Its a lovely start. A couple of areas could use some work, but over all this picture is good.
Lets start with some of the problems I'm seeing and move on from there.
One of the First things to catch my eye is the blue splotches on the floor. They are very distracting. And if they are taking away attention from the main model, then it is something that needs to be adjusted. Perhaps lowering the opacity of it like the red splotch under the piano would be best. Like I said you don't wish to draw attention from the main subject of your scene.
The next big thing I want to address is the lighting. I am expecting this nice polished grand piano, although you have one here, you cannot see it. The use of a couple ambient lights would have been excellent, but a good strong highlight to put a solid shine on the piano would been awesome.
The extra lighting would also have helped you get a better feel for your setting. At the moment it looks like you simply dropped a omni off to the left there, and quite closely to the ground I might add, and then had some simple spot lights used for casting shadows. Sadly it just isn't working for the scene. Adding some of those ambiance lights but extruding them from casting light so they will force your shadows to taper off instead just being solid all the way through would have helped as well.
When I look at this, the wood floor, the white walls (I'm not even sure what your trying to do with those red and blue lights.....) and I think that the best lighting would have been sunlight. Treat it as if there is a big set of windows just beyond the camera and have it flooding the room with light. Use a mask on a spot light to get the feel of the window shape. And then have the strong light on the floor just barely creeping in to the frame.
Now something I tend to get on to a lot of artist for is the size. Give us a high resolution picture where we can see every little detail. Please! I understand that it can sometimes be rather hard on a computer to sometimes render at larger sized images, more details, and extensive maps, but it is truly worth it in the end. You can really get a good feel for a scene when you can just see everything.
Now on to some of the things I like.
I like the piano model. from what I can see, I like. Again this draws back to the lighting issue just a bit, but that has been discussed. At the moment I cannot tell if you used a good bump map or actually modeled each key. Either way I think it looks good.
I also like that you put up some sheet music. so many people do a piano but never give it any music. I feel that a little touch like this in the scene gives the piano a played feel, not just setting in an empty room.
Over all I like the scene and I think it is good. You need to work on some lighting, but other than that, I don't see many other flaws.