I have added a symphony between the verses and, as introduction, a simple statement of the main theme. The symphony moves the harmony back into the minor key ready for the “verse” to begin.
Music in the West Gallery tradition tend to allow singers to stay within a comfortable vocal range. I have transposed the Agnus Dei up from the key I originally chose to one which will not be too low for the soprano and tenor voices. I have also changed one phrase slightly so that the resulting line does not rise to high for altos and basses.