A Mixed Bag is where I try to take my music. Most audiences like to hear new songs but also like to hear one they know so they can sing along. A question to what is new might have to come under the category of "older song but newer audience". Tony Bennet can still do Heart in San Francisco because he still likes doing it. If a performer does a song he/she really does'nt like, then I'm convinced the song will not go over. It has to have that "feel good" vibes or the listeners will tend to turn you off. M.Mario hit on "auto pilot" and I compare that expression as doing a song even when your'e tired of it. Point being if you still enjoy the song when performing it, it should be enjoyed by your audience.
Mudjack