I've been to a number of concerts there (I have relatives in that general area of the world, so it's comparatively easy for me to go there) – can confirm, it is a magical place! One of my concert highlights was Andris Nelsons conducting Die Walküre as a concert performance with the Boston Symphony Orchestra. This opera was separated out into three concerts over the course of an afternoon, with an hour break between each act. Just before the third act was due to start, clouds started building up, and as Nelsons lifted his arm for the upbeat, a massive crack of thunder sounded. It's worth mentioning that the main hall, the Shed, is a semi-outdoor space: there is a roof, but the sides toward the back of the hall are open, and the back is also open to the elements. Then, the Valkyries started singing about a storm brewing, and there was a literal storm brewing overhead! This downpour managed to subside well before the concert ended.Tanglewood
I'd add Rothko Chapel to mine too. Another would be to see a full live performance of Les Espaces Acoustiques. I've seen performances of movements of this piece, but not the entire piece in full. There's a number of modern and contemporary works I would like to see in live performance, and I've been lucky enough to see a good number of these works – but there's many that I have yet to see in concert.The Rothko Chapel has been on my mind recently, so it will be first the entry on my list.