When I watched the Blu-ray of Boulez conducting the Mahler 2nd with the Berlin Staatskapelle, he looked pretty frail to me. I wasn't sure he'd make it through the cataclysmic last movement. He was probably near 80 at that time.
I always like Boulez for modern 20th century pieces. His Stravinsky recordings were the go-to versions when they came out. RIP.
