These guys are no Leonard Bernstein (who is?) but there's some fascinating info on the unpredictability/inevitability of B's harmonic motion, as well as some interesting points about notation and large scale motivic foreshadowing. A bit technical for some, but worth it. The first speaker is not too technical actually....
Simply Sonata: Reflections on Beethoven's Transformation of a Musical Genre:
Late addition: Glenn Gould on how Beethoven invented Schoenberg (Piano Sonata Opus 109):
(not sure why the video uploader kept a self-portrait of herself at the end...)
Tomorrow (Monday) is my 50th post and I'll do something special...?