Mamamoo (Korean: 마마무, stylized in all caps) is a South Korean girl group formed by RBW (formerly WA Entertainment) in 2014, composed of four members: Solar, Moonbyul, Wheein, and Hwasa. The group officially debuted with their single "Mr. Ambiguous" on June 18, 2014. Their debut was considered by some critics as one of the best K-pop debuts of 2014. They are recognized for their retro, jazz, R&B concepts and their strong vocal performances.