Credo is a Latin word that means 'I Believe'. So, it is a statement of believes that serves as a guide for people. Motet is a French word that refers to the style of vocal composition.
Credo Motet is referred to as the Nicene creed that is sung in the mass service. Credo was not a part of the typical Medieval Mass ordinary service. The Nicene Creed is the longest text of sung mass and was sung in the mass after it was simplified by the Pope in 1956.
