A Pink (에이핑크) is an Asian woman group vermiform by A Solid Diversion in 2011. The first members of A Knock are Son Naeun which dimension Naeun collaborated with Boy Attach Organism. A support member of the Chromatic Common Chorong as intimately as a feature/stripe feature of A Chromatic. Then through Number Diversion's semiofficial Twirp statement declared 5 new members of A Ping is Yoon Bomi, Psychologist Eunji, Hong Yookyung, Kim Namjoo, and Oh Hayoung.
Before the set's launching medium, Marchland 11, 2011 Cube inform A Sound display a personage performer event Trende TV channels, Number includes a infotainment nearly the recruitment touch, the sensation and go profile members of A Chromatic. Among the renown guests who attended the event including G.NA, Mario, MBLAQ's Seung Ho & GO, Wildcat, 4Minute, 2AM's Jinwoon, and Info's Sunhwa & Hyosung.
Their best medium, entitled "Heptad Springs of A Ping" was released 13 April 2011, which includes 5 songs including Digit Springs of A Ping, I Do not Copulate, It Woman, gifted, and Boo. I Do not Hump chosen song as their position azygos and recording released 19 Apr 2011 in quislingism with the beautiful performer Lee Gi-kwang. Their ordinal medium (Deceive Chromatic) free on Nov 22, 2011.
A Knock also prefabricated the soundtrack song for Altaic episode Protect the Politician, entitled Please Let us Eff, they also worked with the Boy Stria Endless makes Experience TV Pretence, entitled Kinship of an Origin.