When my husband used to commute, driving long stretches, he would check out tapes from the public library.  That is how he first learned of The Great Courses.  During summers, when I would be with him, we listened to Bart Ehrman, fascinated by the revelations (pun intended) he made about the "Early Christianities."  It was when we tried to play "History of Ancient Egypt" that we had a real shock.  "Something's wrong with this tape," Bill said.  Turns out, it was a DVD and not a CD.  So we watched Bob Brier explain the history.  Works well in either format, the advertisements read.  And so they do.
     Lately, we get catalogues regularly, and we have learned about economics and other delightful subjects.  But we didn't make it through quantium mechanics.  (Maybe we'll tackle that one again, later.)  I've just ordered lectures about Nietzsche.  I have read so much by and about that philosopher, but I still don't understand as I want to.
    In the middle ages, when books were rare, lectures made up the difference.  There's still the excitement of going to a conference versus reading a book.  But now, books are cheaper, and the internet provides so much information.  Even though I've taught "History of the English Language" myself, I want to hear "Myths, Lies and Half-Truths of Language Usage" by John McWhorter of Columbia.  Somehow, I think he'll be a better teacher than the one I had at Syracuse University in the 1960s, who asked his class, all graduate students in English, if we knew what a "helping verb" was.  (But I did  learn a lot of linguistics, however reluctantly, enough to know my grandmother had it all wrong, teaching me how to diagram sentences when I was in fourth grade.)
     Anyway, let me recommend The Great Courses, if you haven't found them already.  You can always ask your librarian to purchase the ones you relish.  Visit www.THEGREATCOURSES.com or call 1-800-2412.