I was at a concert for kids today at the Royal Albert Hall (I know - v mumsnet!) with my 2 DS and husband. Live orchestra, playing classical and film music. It was under 2 hours, with an interval. The family next to us had 3 kids, aged btw 4-9 at a guess. For the ENTIRE show they talked at full volume, ate crisps and popcorn constantly, got up, jumped around and at times fought with each other. At no point did the parents intervene, apart from chatting to their kids about random things, again at full volume, and opening yet another packet of loud snacks.
Tickets were not cheap - £30pp, and this was a special day out for us, disturbed not only by this family, but plenty of us who treated the whole thing like they were watching it in their living room. At times we couldn't hear the music as the chatting and eating was so loud.
It showed a total lack of respect to the musicians, singers and actors, as well as their fellow audience members. I'm not expecting kids to be silent little statues, but surely most children can sit without needing to eat for 45 mins at a time, and can be taught to whisper if they need something, rather than chat at full volume. There are also quieter snacks than sodding hula hoops and popcorn!