actually, they do sing, it look me time to figure it out, but the 4 main dancers sing in the chorus and in the bridge, toi can hear a very distinct voice from them. in the first chorus toi hear sooyoung, in the seconde chorus toi hear sooyoung and yuri, in the bridge toi hear sooyoung, yuri, yoona and hyo, and in the third chorus toi hear hyo again.
I NEED A TIME MACHINE~~ i'm a ballad lover, hehe.. this song is perfect.. i l’amour it soooo much.. i heard that it was about -1C when yoona's cry scene.. yoona's acting.. JJANG!!