The Karajan recording of the 6th was my first introduction to the symphony.
Very fine performance indeed. It captures the full emotion of the work.
Karajan Mahler Six
https://dgt.link/karajan-mahler6
I found this fascinating. I particularly enjoyed the separate machine used for the bells. If this link doesn’t open search YouTube for Karajan Mahler 6 Emile Berliner
The YT extract sounded amazing.