A successful ministration depends on the people who are well fed, well catered for, spiritually, physically and are emotionally and mentally stable to deliver their parts.
so an effective choir ministration goes beyond effective part teaching
have you not seen where a music director will come to rehearsal and teach, you will get your part very well and the song will be like wow. and on Sunday, you will be given alto like alto and you will be singing soprano. what is happening?
Somebody has just gone through problem at home that when they are singing, they will be giving the part that their problem has given them and no longer the part that you needed.