Hi John
Everyone has their own method I guess, but I put each song in an SD location and within this, have 4 PM's set up for variations and change of instruments. I then put the chosen songs in Favorites for performance.
pa4X 76 ,SX900, Audya 76,Yamaha S970 , vArranger, Hammond SK1, Ketron SD40, Centerpoint Space Station, Bose compact