The term 'Whistlers' Whistles' is a phrase used to describe the tunes that are played by whistlers. Whistling is an ancient form of music-making, and it has been used for centuries to create melodies and rhythms. The term 'Whistlers' Whistles' refers to the unique sound created when a person whistles a tune. The crossword solution for this term is 'TUNES', which accurately describes the type of music created by whistlers.