Setting the Song Genre
For most bands, there will be specific songs that they would want to perform. Depending on the theme and familiarity of most of the band members, the more songs you know the better it is for you to get to the top.
The thing about bands today is that their limitations as far as songs are concerned becomes a limitation for them. The places where they would want to perform have preferences as far as which songs to carry. But on the part of the band, sticking to a particular genre creates identity for them. While many would not understand it, it is all about branding in the music industry.