CET,Depends on the day of the week you go. Normally, Wednesday and Thursday are quieter nights and I will request odd songs which aren't your usual Irish Pub fare.
Evans & Doherty judge by the audience at hand and go where the energy level seems to be. If there is more of a listening audience, they'll sing some of the more ballad type songs.
Most good bands will go the way the audience seems to want.
If you want to make suggestions, write it down and send it up to the band on the stage. Worse thing is they won't do it!
The information I had from castlebay was they were here between Sunday and Tuesday nights, leaving Wednesday, so I haven't offered the sessions on Wednesday.