Mansionz (stylized as mansionz) is an American alternative hip hop duo composed of American singer-songwriter Mike Posner and American hip hop recording artist, producer, and singer Matthew Musto, better known by his stage name Blackbear. They released their debut studio album, Mansionz, on March 24, 2017. Mansionz was formed when longtime collaborators Matthew Musto (otherwise known as Blackbear) and Mike Posner formally came together and formed an R&B-rap duo.