Several people have written to ask for some relatively simple music that would put a choir on a new track toward solemnity. For the choir, the goal of the first pieces of music are to 1) get the choir used to singing without instruments, 2) help with the stability and sound, 3) eliminate vestiges of popular styles such as ego-swoops and the rest, 4) help to create a new understand of rhythm that is free and flexible, and 5) provide models for working on chant-like phrasing
For the congregation, these pieces help familiarize people with a sense of our timeless heritage. They are not all super easy by modern standards, and all will require lots of rehearsal time, but as these things go, these are 10 of the most approachable.
I don't need to say that this list is wholly subjective. There are tens of thousands of possibilities but these are my choices based on ease of singing and beauty of the piece itself:
1. I Heard the Voice of Jesus Say (Tallis, the original score with melody in the tenor line).
2. If Ye Love Me (Tallis)
3. O Esca Viatorum (att. Issac)
4. O Bone Jesu (att. Palestrina)
5. Jesu Rex Admirabilis (att. Palestrina)
6. Voce Mea (G. Croce)
7. Virtute Magna (Croce)
8. Adoremus Te (att. Palestrina)
9. Ave Maria (Arcadelt)
10. Lord for thy Tender Mercies Sake (Hilton)