Earl
Break the projects down to small pieces. 30 songs is a big job to find Styles/Sounds for. I like the headphones idea too. Work until you find yourself getting off target. Then stop for awhile ( or more ) and go back. Even when I'm feeling sharp I can't practice more than two hours before I lose concentration. Sometimes I may have only 20 minutes free but really try to stay on task and tell myself I took one step forward in my goal.