I seriously would call an usher on a child and his/her parent if I even hear them mutter a word during the songs.
Though when I saw GYPSY last week it was an older lady that I had to ask to quiet down because she was singing the lyrics to the songs from the overture, so it may not only be the children the ones that will need some punching.
It is the actors I want to hear singing not the audience.
Videos