“Shock” is a song by the South Korean boy group Beast. It’s the first single from their second EP “Shock of the New Era” which was released on March 1, 2010 along with the EP. The song introduced a new genre called Rocktronic, which is a combination of rock and electronic music.
A Japanese version was released on March 16, 2011 which serves as their debut single in Japan. It ranked #2 in the Oricon daily and weekly chart with 28,532 copies sold in the first week, beating the debut single of Big Bang’s “My Heaven” at no. 3 in 2009.