If I had had the foresight to bring along a cassette recorder, that would have been the context. But I didn't, and neither did anyone else. Of course, there's no way I could have afforded the large number of cassette tapes, either, so the point is moot.
It's too bad all those lectures are lost to history.
I may even have a box of them somewhere around here in the barn.
Not too surprising given that a cassette tape in the 70's cost several dollars (equivalent to maybe $20 today). It was so expensive it simply didn't occur to people to record such things.
It's like photos. The cheapest 35mm photo cost a buck an image, and this was for slides, not prints. It's why photos of my college career are nearly non-existent. And movie film - forget about it.
I recommend digitizing them. Cassettes don't last forever, and you'll probably enjoy hearing them again.
But reading the notes later would cause me to recollect what was said, and so the notes were very useful. Unfortunately, enough time has passed that I've forgotten what was said, and only have the notes.
It's like watching a sitcom with the sound turned off :-/
As for lectures in the past, it is a shame we may have lost them, as it seems to me (purely speculatively) that the lectures from the 70s and 80s seemed to make a whole different class of programmers to the ones of today. Or maybe it was the tinkering and not the lectures, who knows.