I want to point out one particular site which has midi's recorded "live" from an absolutely fantastic pianist - Doug .

I've copied them onto my PSR 2000 and they are simply stunning.
http://www.pianoman.myweb.nl/

If you then use a program like MidiNotate - http://www.notation.com/ then you can get it to regenerate the notation and try and play along. (You'd better be good...)

Jerry
Amsterdam