The crossword solution for the term 'Tune (Theme Song)' is 'SIGNATURE' with 9 letters. A SIGNATURE tune, or theme song, is a piece of music that is associated with a particular person, group, television show, or product. It is often used as an introduction to a program or advertisement and can be used to identify the source of the music. SIGNATURE tunes are often composed specifically for the purpose of being used as a theme song.