TOD: When I was a teenager, I saw Peter Leonard conduct Mahler's first symphony, Titan, with the Louisville Symphony Orchestra. That was an eye-opener for me as far as classical music was concerned.
When I lived in upstate New York, I managed to get to Tanglewood for what turned out to be Bernstein's last concert, Beethoven's Symphony No. 7 and Britten's Seascapes from "Peter Grimes." He was supposed to conduct his Arias and Barcarolles with Judy Kaye, but he was too weak for that. I forget who conducted that. It was a rainy August afternoon, and it was cold, in the 40s or 50s. Sitting at the back of the amphitheater was OK because we had managed to get some space under the overhang, but people in the open stayed put, too. And the support and energy and good vibes they gave Bernstein were palpable. He didn't move much, and he skipped the break between the last two movements, but he was in control, using his head to nod this way and that while his hands were holding him up.
Weirdest concert was in the wine cellar of Clos Pegas in Napa Valley. The program was of German composers, and the damp atmosphere of the setting affected the instruments. The musicians would tune up for a long time between pieces, but by the end of a 10-minute piece, you could hear pieces just get a little off track. It wasn't by much, but it was a good lesson. Everyone had a good sense of humor about it, especially the musicians. So, perfect setting, somewhat imperfect music. Didn't matter. Memorable evening.