Earlier you heard BEAST with Ready Go for the God of Study OST (Soundtrack Part 2). Now you can listen to f(x)'s Luna, Krystal, and Amber sing ??? ?? (Spread It's Wings) for the same soundtrack. Both Luna and Krystal have beautiful vocals and Amber's rap is on point. This is probably the best song on the whole soundtrack, check it out below and also check out Aff(x)tion. http://www.youtube.com/watch?v=vPXMmVyTLuI