Do you audition the children?
Without going into too much detail, if it's just a choir to represent the school at local events and not a competition, would you exclude any child who showed an interest in singing in the choir?
A school in my area has done this to some year 6 children - they were all told that the songs don't suit their voices when they auditioned and so couldn't take part in what would probably have been the highlight of their final school year (funnily enough all the popular sporty yr 6 boys were there for the first time) The choir was big enough to have absorbed their voices I think (and my specialism is voice and adult choirs).
I thought this attitude had disappeared long ago, and can imagine these children as adults being afraid to join a choir because of this teacher's decision. On a weekly basis, I work with adults who have been left feeling they can't sing their whole lives because of choirmasters like this at school.
Anyone else do this and what's your justification for doing so?