Be very careful with light. Use flashlights that have give off red light. Keep the car headlights off. Keep young children under control. There is a lot of expensive hardware around for them to run into.
Sound carries well at night.
I enjoy music but not everyone has the same tastes as I do, so I leave it off. Even that cosmic new age stuff can be an imposition on some people. A key to success at any observing session is to plan on it getting colder than you might think it will be. Always dress warmly, even in the summer. Seeing Seeing is the ability see through the atmosphere.