In 'Crouching Tiger, Hidden Dragon,' the quote 'No growth without assistance. No action without reaction' reflects the film's martial arts philosophy. To mirror this, composer Tan Dun utilized the erhu, a traditional two-stringed Chinese fiddle. The erhu's sound is famously close to the human voice, capable of expressing deep sorrow and soaring honor. In the film's most legendary scenes, the erhu engages in a 'musical duel' with the cello, played by Yo-Yo Ma. This symbolized the meeting of Eastern and Western cinematic traditions. The instrument's ability to slide between notes (glissando) perfectly complemented the fluid, gravity-defying movement of the Wuxia legends. The score helped popularize the erhu in the West, showing that traditional folk instruments can carry the narrative weight of an epic cinematic legend and its philosophical dialogue.