How exactly does the underage section work?

Due to Arizona State Law, our all-ages shows must include a barrier between our underage guests and those who are 21+ (who have access to alcohol). Incidentally, this is why we request that our underage guests use the south entrance of the Music Hall (only open to underage guests on show nights) after receiving their wristband; rather than pass through the north Music Hall entrance or Rose Room. Underage guests must form a line outside the venue until doors open. There is no access to the restaurant area (Rose Room) and no re-entry for underage guests.