Listen to Mass in C minor, K.139 "Orphanage mass": Credo: Credo in unum Deum online. Mass in C minor, K.139 "Orphanage mass": Credo: Credo in unum Deum is an Unknown language song and is sung by Peter Neumann/Collegium Cartusianum Köln/Kölner Kammerchor/Barbara Schlick/Ulla Groenewold/Markus Schäfer/Klaus Mertens. Mass in C minor, K.139 "Orphanage mass": Credo: Credo in unum Deum, from the album Mozart: Sämtliche Messen / Complete Masses, was released in the year 2011. The duration of the song is 2:10. Download Unknown songs online from JioSaavn.