Recording and writing for the album roughly began in the summer of 2010, but full production did not begin until August 2010, after Yunho and Changmin debuted their first performance as a duo at the SM Town Live '10 World Tour concert in Seoul, South Korea.
head | head of state | Beavis and Butt-head | Alec Head | Murray Head | Head Start | Anthony Head | Head Start Program | Diamond Head | Human head | Head teacher | Machine Head (band) | Machine Head | Head Over Heels | Head of the River Race | Eddie the Head | Hilton Head Island, South Carolina | Edith Head | Diamond Head (band) | Beachy Head | The Bodley Head | Lizard Head | Head & Shoulders | Head over Heels (Paula Abdul album) | Head over Heels | Diamond Head, Hawaii | Women's Head of the River Race | Turk's head knot | The Top of His Head | Roy Head |