Four months ago I appealed to bands everywhere, reconsider the modern encore. It seems none of the bands have heard my cry. So, I will be a bit more civil and make a smaller request.
I accept that an encore will be played, but I ask that you limit it to three songs. Last week I saw Brendan Benson and he had a six song encore after a mediocre set. This is unacceptable. Here is the formula for a perfect encore.
First Song: There are two ways to play this. If you are a singer/songwriter then you can come out by yourself with the acoustic guitar and sing a heartfelt, solo version of a song people know and love. The other way is to just come out and rock the fuck out of a song your fans love. They will think, "Oh man, I totally forgot about that song! Thank God I stayed for the encore!"
Second Song: Here's your chance to be a little experimental. You can either play a new song, a new version of an old song, or bring out a special guest of some kind. You figure people who are sticking around this long will want to hear something new or different.
Third Song: Bring it home. If you brought out a guest musician on the last one then let him/her stay on and clap if that's all they can do. It doesn't have to be your most popular song but it should be fun and engaging. If the crowd is still going crazy after this song and people start chanting, "One more song! One more song!" then you can bring out a fourth song. And if you let the audience choose it, be selective. We don't need to hear that b-side from the third single on your first album just because the guy in the front row wants to show everyone he's your biggest fan.
I think this is a fair guide and I encourage you to print this out and give it to your favorite band. If I know this band, I would even be willing to custom tailor a list for them. I'm that committed to improving encores worldwide.