You will certainly find competitive piping and Highland dancing at Highland games, but fiddles, harps and sessions are not usually [ ever ? ] part of an official programme, in my life-time experience, anyway.
The only exception I have ever come across is the Aboyne Highland games where Paul Anderson judged a fiddle competition. That was about 4 years ago. If you do come to Aberdeenshire, post here when you are coming, and I will let you know what, if anything, is going on at that time.