What is signature song?

A signature song, also known as a theme song or signature tune, is a song associated with a particular artist or group. It is a song that is considered to be their most popular, well-known, or representative work, and is often associated with their identity and style. Signature songs are typically recognized as their most successful and memorable hit, and are often played at live performances, used as the title or lead single of an album, or become the artist's calling card. For instance, Elvis Presley's "Can't Help Falling in Love," Queen's "Bohemian Rhapsody," or Michael Jackson's "Thriller" are all considered their respective artists' signature songs.