Zhang Li Yin
In early 2007, Li Yin promoted the second track of her debut single called "Y (Why...)", which is a power ballad. SM Entertainment also released a "Timeless" documentary version of her "Y (Why...)" PV. It featured her hardships while training, as well as many behind-the-scenes clips of her promotion of "Timeless", including never-before-seen footage of her and Xiah Junsu.