The original key of the main theme song for Popeye by Fleischer Studios is C major. Composed by Sammy Lerner, the Popeye theme song was performed by various artists over the years, including the voice actor Jack Mercer, who provided the voice for Popeye in the animated series. The song served as the iconic opening theme for the Popeye cartoons produced by Fleischer Studios and later by Famous Studios. A trivia about this song is that it features memorable lyrics such as "I'm Popeye the Sailor Man," which became synonymous with the character. The melody of the main theme is characterized by its catchy and upbeat rhythm, reflecting the adventurous and comedic nature of the animated series.