The next week at school, Mariana and all her friends “keep saying how great the party was and how much fun [Greg’s] mom was (174). Greg has lost interest in the band, not just because the party is over, but because some of the boys in the band have been “giving [him] a hard time” (174) about his mom showing up to the party.

Greg tells his parents that he wants to quit the band, but his father refuses to let him. He says that Greg needs to “honor [his] ‘commitment’” (175) and learn about perseverance. Greg tells his father that he will keep trying, and believes that he is “off the hook” (175). However, Mr. Heffley tells Greg that he is going to come to the band’s Fall Concert to cheer him on. Greg tries to get Rowley to help him learn to play the French horn, but the two keep getting distracted. Mr. Heffley gets upset with Greg and sends Rowley home.

The day of the band concert arrives. Greg still cannot play his instrument, but he figures that if he sits next to Evan Pittman, the other French horn player, during the concert, no one will notice.