Mason Dixon: Fourth-Grade DisastersBy: Claudia Mills Illustrator: Guy Francis Series: Mason Dixon Here's the second entry in Claudia Mills's charming middle grade series, that finds the lovably sardonic title character starting the fourth grade, which he's dreading because everyone in fourth grade is expected to join the school choir. And sing. In front of everyone. Mason can't think of many things he enjoys less than singing but performing in front of other people might come close.