Hmmmm
I don't know your equipment at all, but I have a couple of ideas.
1) Assuming that the whole piano instrument seems sharp, and not just a particular register, you can detune the piano instrument a certain number of cents until it sounds right to your ears.
As you may know, there are 100 cents in a semitone, so if your notes sound sharp, detune your piano track from the synth or sample module that it is playing from. Start with -5 cents, and if that's not enough, increase to -7, then -8, etc.
2) The alternative, and more difficult method, is to program a MIDI command at the beginning of the track to pitchbend downward a small amount, and not to reset throughout the whole song.
I found a link on Cakewalk forums that address this issue and your technical need quite well. Here's the link:
http://forum.cakewalk.com/tm.asp?m=1486576&mpage=1&key=exaggerated?
Pay special attention to the MIDI range for pitchbend of (-8192 to +8191), and try to understand what is involved so that you can determine what value to enter in your pitchbend range command, to effect the whole piano track. Good stuff in that forum.
But by far, the most simple answer is the 1st suggestion I gave. There is always a way to detune patches, i.e. oscillators, in a synth.
