It actually surprise mi !
SM actually gave more part to yoona (in terms of singing) and I personally feel that she has improved ((: to proof this point , ppl pls listen to music remove version of the mv !! ((:
Also , yuri n singing got more front dancer roles ((: love to watch them ((: esp YURI !!
And And … Yuri Sooyoung Yoona n Hyoyeon were rapping ((: