Which American singer appeared in music videos for R&B group B2K and also featured on the mixtape Detroit by American rapper Big Sean? 
Detroit (mixtape):  American singers includes Chris Brown, Jhené Aiko, James Fauntleroy and Mike Posner. Jhené Aiko:  She embarked on her music career contributing vocals and appearing in several music videos for R&B group B2K.
Jhené Aiko