Theatre in Berlin/Germany during Summer?

Hallo Kinder

Dumb question for an Aussie travelling to Berlin in July-September for some short-term study: Do the theatres (by this I mean for plays and musicals, not the cinema) close over summer? I'm trying to book shows ahead of my trip and I don't see much past the first week of July in Berlin.

Also if anyone has any recommendations for theatre - not just in Berlin, but throughout Germany - I'd love to hear them.