An aspiring rock star named David Dinger (Luis Avalos) from rock 'n' roll's earliest days would hum his songs because he could not remember the words: critics dub him the Hum Dinger. By 1960, the hits stop coming and he works as an electronics repairman. He defrauds his customers by revealing phony hums in their equipment. Spidey investigates and tracks Hum down at the home of a customer (Judy Graubart) and her son (Todd Graff), foiling him by leaving a radio turned on until Hum could no longer maintain his hum.