It is silly to think that Masses of this nature, which could be sung only as a concert and not as a Mass, should not be sung as a Mass. It lifts people's spirit in order that they might actually participate in the Sacred Mysteries.
Pope Benedict said this today about Mozart's Coronation Mass: "It remains indelibly impressed in my memory how, for example, as soon
as the first notes resounded from Mozart's 'Coronation Mass,' the
heavens practically opened and you experienced, very deeply, the Lord's