According to Otto Ursprung, Cantus missae is the “most beautiful, pure vocal music of the 19th century”. This is Rheinberger’s only Mass written for double choir. It obtains its special character through the use of compositional techniques of ancient classical vocal polyphony, which are combined with functional harmony and expressive, songlike voice-leading. Rheinberger was honored for this Mass with the Gregorius Medal in 1879 by Pope Leo XIII.