Powers: If it finds a singing voice that it likes it will mimic that voice, as well as whatever song the person is singing
Captured in: Episode23: Sakura, Tomoyo, and a Wonderful Song
How it was captured: Song had mimicked Tomoyo's beautiful singing voice. Sakura was able to lure Song out by having Tomoyo sing. Song appeared to sing a duet with her, and Sakura sealed it away.