If you've never been, by "indoors" I mean in the seats under the roof. It's still open-air on the sides and back. If there's a breeze, it's really nice.

Much more casual. People on the lawn will be wearing shorts. For the symphony, the people indoors may at least be wearing pants or skirts, but feel free to be cool and comfortable.

Yes People will be casual for the most part

Is it more casual than the Kennedy Center? Going to hear Beethoven's 9th.

Thanks!