This sound is best known as the Rocky training theme from the Rocky franchise, commonly recognized as “Gonna Fly Now.” The music was introduced in Rocky in 1976 and became closely tied to Rocky Balboa’s workout and running scenes. Over time it spread far beyond the films into sports edits, comedy training parodies and motivational videos online. People still use it because the melody signals effort, perseverance and eventual triumph almost instantly, even in a very short clip.