A performance from 1964 with the Swedish Radio Symphony. This was the opening number! Some of the other pieces from this performance are on YouTube. It appears to be a very formal concert - perhaps a Royal Command Performance. This is the Royal Concert Hall in Stockholm, conducted by Stig Westerberg. I welcome details if you know them.
The performance is incredible. Check out the relaxed easy posture while Nilsson puts out an ocean of sound! Someone has finally posted the complete performance here: https://youtu.be/yYjMCQ9xq5I