Apart from being a genre-straddling musical genius, Leonard Bernstein was also a great talker.
Here is an excerpt from his "The Unanswered Question" lecture series at Harvard.
Lengthy theorising about music can often make me just want to go and mosh to something dumb and primal like the Stooges, but I do love Bernstein's interpretation of a section of Beethoven at the start of the clip: