Check out the Robert Greenberg tapes (easily googled). He did a 45-lecture series on the complete history of music, he's very entertaining, I've learned a lot from him; and his tapes have the added bonus of putting me to sleep during jittery markets. He also has series of lectures on: opera, Beethoven and the concerto. [Edit: and many many others thru The Teaching Company; my info was 15-years out-of-date.] They are very expensive but my library has them all and will buy anything he records because the librarians love his live lectures. The concerto series is over-my-head but the others are okay for anyone. Also, any large symphony or opera may have tapes or CDs for sale on individual operas or other musical works. Often there is a 1/2 hour lecture before performances. I've never met a music lecturer I didn't like; they are invariably infectuously enthusiastic. Books I've seen (or bought) are dismal.
Great idea, R-Robert, that's just the kind of thing I would plan to do in the big R.
