D-11 ♫ Just your collection line, easy access line ;
August 2010 — ;
A teaser was released on the 4th, revealing the new, fierce and sexy concept taken up by the colorful group Rainbow, for their first digital single, A. The girls make a mark with their key-point step ab dance, in which they lift up their shirts to expose their midriffs.
A debuted on the 13th, with the girls performing the song on Music Bank. Eventually, Rainbow makes their comeback with Mach, which was released on October 20th, with their performance airing first on M!Countdown in the following day.
