History of Album Cover Art

I'm thinking about album cover art and found this cool Flash presentation (from the Eisner Museum of Advertising and Design) on the history of album cover art, here. It's not only a cute and quick retrospective, it's a nice demo of Flash, with a spinning record and music of each era playing, plus explanations of how each cover design came to be. I really like the old Blue Note jazz covers--often just three colors, black and white photography with primary-color type.

There's also a cool blog on the topic of CD covers from a graphic designer, here.