OK...how about Metallica....in Moscow!!!
My wife and I spent a week there and caught them at Luzhniki Stadium in Moscow, holds 70,000 fans. We were about 15 bodies deep from the front of the stage. The energy in the stadium between band and crowd was unlike anything I have ever seen. The band was in top form and played many of their classic songs. Met many friendly people there.
One interesting note from the show was the military presence at the show - standing within the floor level inside the stadium, and throughout the entrances and exits to the arena. Certainly an experience!
I also ran into an impromptu live vocal performance while I was visiting one of the cathedrals. A five person vocal performance in a brick walled cavern off in one of the buildings. The voices started with a hum and broke into a beautiful piece - the lead vocalist had a magnificent bass that was deep and filled the room without electronics. I immediately wanted to capture this sound. Turns out they had CD's for sale. I bought one to hear on the Axioms - hopefully I can recreate that sound I heard. I believe the name of the group was Dvoros (or something like that).