I believe children under 2yrs are free but the child must sit or be on the parents lap during the entire performance.
Is free
I found this that may be helpful: Children under 23 months are admitted free provided they sit on a parent or guardian's lap. Children over 2 years old require a ticket. So it appears that the answer is yes... 9 month olds are free.
I have no idea. I went to a rock concert.
Thanks! Your answer is awaiting moderation.