Now this is a find: The New York Philharmonic has a Digital Archive online featuring a wealth of material. One great part is the programs from the NY Phil concerts. For example, I did a search for ‘Donizetti’ and came across the program for a 1950 concert.
[Note: as of August 2017 seems the images of the booklet are now missing, but will leave up link in case it gets fixed sometime]
There is a scan of the program with great info on the works, performers, and of course those great 50’s era adverts. Plus there are links to images of the scores of performed works at the concert. These days a bargain CD release or MP3 album has absolutely no notes on the music or performers, and the archive is an excellent resource. Currently there are no audio or video clips but hopefully these will appear one day.
Be warned, you can get lost searching and reading 🙂