I am planning a 3 week trip to Europe this time next year. I've been a couple times before and have gotten extremely lucky and been able to travel very shoestring. One of the things that made my trip so cheap was I just accidentally stumbled upon some amazing free culture events just by wondering around. Since they were accidentally, I don't know what they're called! One particular one that sticks out in my mind is a free symphony performance at Schönbrunn Palace that I just happened to be at the palace that day for. I am wondering if there is any kind of consolidated list of these kind of events? I know that is a big ask for the entirety of Europe so I guess I am maybe just wondering country by country? I am trying to plan my trip to include some of these events. Thank you!