Ability: Except for O Beata Benedicta, there are drone notes in each piece. These are intended to 1.) add beautiful harmony to the sound and 2.) provide an good option for any of your singers who may be unable to sing some of the harmony and yet allow them to participate in a meaningful way. Please assign singers to these drones as you see fit.
Changed Voices: Any of the changed voices are welcome to sing this music either in falsetto if they can (I have a couple boys in my boy choir who will be doing this) or they can sing an octave down on any of the drone notes.