I was interested in doing a looking outwards for this project because I had a very similar idea a couple months back. I always found self playing pianos to be unintentionally creepy, which could be a big asset if spun the right way.
In MirrorFugue the artists created an installation, where recorded videos of pianists playing are projected back onto the glossy surface of the instrument, as it self-plays the same piece. The fingers look like they are moving the keys, the pianists expressions add an emotional quality to the piece that would not be there without the image.
Although this piece was not actually interactive, I think it could have been. They could have used real time video feed from a different location, or could have rigged a pre-made 3D model to different piano pieces, etc. I think the piece is effective in the context of memory analysis and emotional study, however maybe lacks in complexity.
Here is a link to the MIT Tangible Media webpage.