The original key of the song "Athletic" from Super Mario Bros. 3 is F major. Composed by Koji Kondo, the song serves as the background music for the athletic levels in the game. Kondo is a renowned video game composer known for his work on various Nintendo titles, including many iconic pieces for the Super Mario series. The melody of "Athletic" is characterized by its energetic and upbeat tempo, perfectly complementing the fast-paced gameplay of the levels it accompanies. A trivia about this song is that it was featured prominently in one of the most popular and critically acclaimed games on the Nintendo Entertainment System (NES), adding to its lasting popularity among fans of the series.