What did Paul really feel about being in the rock band? Why did he continue?

Paul’s development and maturity is shown again during the Battle of the Sounds competition. Although the band wins the competition, Paul does not enjoy the victory. He realizes his own distaste for Rough Stuff's type of music, which is another instance of his process of developing his own tastes and desires.

The more time Paul spends with the members of the band, the more he realizes that both the type of music and the band's dynamic are not for him. Paul's involvement with the band is a diversion from his focus on the piano, but in the end, it makes him realize how important piano is to him.