As soon as you start talking about performing, you talk about connecting with your audience. And, as each audience is different, and each night is different (even when you are coming back to the same place to sing,) I find it best not to have too many preconceived ideas about which songs I am going to sing. Often, it has less to do with whether particular songs (ones I've written, or traditional songs)are "good" than it does with what people respond to that night.
There have been times when I've peeked around a corner and got a look at the audience and threw my set list out the window.

A good performer should know which songs are going to be enjoyed by the time they're into the third or fourth song of the first set. You can sense how the audience is responding to different types of songs and adjust you set list for the evening. For me, set lists are a guideline, not a "program." It's probably been years since I followed a set list completely.

Much of performing is placing the song in context with the songs immediately before and after it, and how the song is introduced. As Genie points out, a song may go over well with one audience, and get very little response from another. I also remember a concert that I did that had an overflow audience (rare for me)where the audience looked like a herd of cows chewing their cud. No one laughed, or even smiled at my introductions, and they might as well have used their hands for paper weights. I thought I had really failed to reach the audience until the concert was over, and suddenly everyone was animated, and I sold the most cassettes I'd ever sold. They just weren't a demonstrative audience.

The other side of this has been stated most succinctly by Ricky Nelson in Garden Party. There's a real danger in just doing the songs that have receive the greatest response. You don't want to become an "oldies" act. I can think of one performer in particular who I booked many times, who used the same set list, and I swear I could have done his introductions, because I had them almost memorized, word for word. The performer mailed in their performance, and I finally stopped booking the performer.

Performing is connecting. It's as simple as that. A good performer connects with the audience, and sets aside songs that they know won't be enthusiastically received that evening. The next concert, that same song may bring the house down.

Finally, some of the songs I've written that I think are at best throw-aways, have been enthusiastically received by some audiences, and have even been recorded by other musicians. Your own evaluation can be as innacurate as can a particular audiences.

You can do a fine song for an audience that doesn't appreciate it, too.

It finally comes down to being aware of the audience that night, and making that connection with them. The rest comes naturally.

Jerry