First rule: Play what you know. If that's not enough, ask for requests.

When the time comes to learn something new, learn one you like for every one you learn that "they" asked for. If you can find out, learn at least one song the owner of the establishment you're playing likes; also one that his/her spouse likes

Learn one or two songs that the help suggest - if you get them on your side, you're a lot closer to winning.

Finally, and perhaps most important, learn at least one song that "she" likes (whoever she may be).