A sometimes-dissonant quartet of anthropomorphic instruments continue to weather ups and downs at summer camp.In their debut, the campers of Bunk J-Zook the kazoo, Kaylee the ukulele, Cordelia the accordion, and Trey the triangle-found harmony in time to triumph in a camp-wide competition. Now they're pitted against their nemeses in Bunk M for a game of tug-of-war. As usual, Zook is full of himself, but Cordelia slips, and they end up sliding to third place. Bunk J's trash talk irritates some of the other campers, who plan to divide the team; when Cordy can't get over her mistakes, they see their chance. Kaylee suggests a surprise party to bolster Cordy's self-esteem, but their planning lacks all discretion. Cordy's convinced that her friends are dumping her, and their clumsy manipulations reinforce her angst. The next camp challenge is a group hike up Piccolo Peak, and Cordy channels her insecurities into training. The hike is canceled due to rain, but Cordy's already set out. Now it's up to her friends to rescue her. Conflict, excitement, and cartoon mastery compose a siren song for young readers. The round-eyed, expressive instruments cut adorable figures in Smith's art, and Bunk J's antics and support for one another are appealing.Pitch-perfect and fast-paced, this series hits all the right notes. (Graphic chapter book. 6-9)