 Jack s guests, the pop singing group The Lettermen, provoke surprisingly strong reactions from Jack Benny and his regular singer Dennis Day. They bump Dennis from singing on the show at all, so he skulks behind the scenery as the Phantom of the Comedy. Jack, The Waukegan Wizard, claims he earned a high school letter as a cheerleader, but regrets he didn t attend college, so the World s Oldest Freshman enrolls with The Lettermen.