NO , it is illegal. As good an idea as this is, and as helpful as it would be to teach the music to members of the choir, it is against the law without permission. Write or call the publishers of the music. They will inform you of their requirements concerning your request. Duplication of copyrighted materials is against the law when the purpose avoids a legal purchase.
Embarrassment is the first.
Additionally, the law provides for the owner of a copyright to recover damages for unauthorized use of copyrighted music. Frankly, we cannot imagine what kind of school, church, or professional musician would derive satisfaction from doing something illegal. They force the price of legal editions higher. They risk embarrassment from professional colleagues who understand the law. They risk fines and jail sentences if taken to court.