Quiet extraordinary, it seems the Fisher Centre in NY - home of the Bard Music Festival - make available on-line , free of charge, previous years programs. This is the program to the 2009 festival which as it name suggests concentrated on Wagner. What you will find is rather beautifully illustrated series of essays spread over 90 pages on the life, times and work of Richard Wagner. Highly recommended. can I also sugget you check out other years where they have similar coverage of Sibelius and Liszt.
More details of the Fisher Center can be found by clicking here: Fisher Center For The Performing Arts