Mamamoo (Hangul : 마마무), sometimes stylized as Mamamoo is a South Korean girl group formed by Rainblow Bridge World (RBW) in 2014. The group officially debuted on June 19, 2014 with the song "Mr. Ambiguous". Their debut was considered by some critics as one of the best K-pop debuts of 2014. They are recognized for their retro, jazz, and R&B concepts and strong vocal performances.