"The Singing Critic" aired on November 5, 1949, as the 29th episode of the series. In this episode, Diamond takes on a case involving a song-hating neighbor who is causing trouble by criticizing local talents. The plot follows Diamond as he navigates the comedic absurdities surrounding an operatic critic while showcasing both his detective skills and a flair for musical humor. The character is put in humorous situations involving his singing, where he ultimately performs a light-hearted song titled "A Hundred-and-One Tons Of Fun" after solving the case.