I just discovered a wonderful graphic designer named Alex Steinweiss who was responsible for the invention of album cover art in the late 1930's. Here's a bit of history from the Alex Steinweiss site:
Before Alex Steinweiss invented the album cover in 1938, at the age of 23, all albums came in plain brown wrappers. Steinweiss's idea to create a package that had something visual on the outside to lure the consumer was a huge success. That simple idea revolutionized the record business and spawned an entire new field of illustration--album cover art--that is now inseparable from the product it announces. Steinweiss's covers are still regarded as icons of the genre. He designed them as miniature posters, with eye-catching graphics, distinctive and vivid colors, and creative, original typography. He was an accomplished illustrator, and he incorporated original artwork into most of his pieces. The Steinweiss style went hand in hand with the golden age of jazz, classical, and popular music.
Follow this link to the Steinweiss covers page which has over 70 examples including the one with a cool collage treasure dot shown above. My first LP was "Rubber Soul" by The Beatles. I miss that large 12x12 format. Today's CD's are too small to do their artwork justice, but I guess that's progress for you.
Taschen has published what looks to be a great book on Steinweiss. There is also a biography, For the Record: The Life and Work of Alex Steinweiss on Amazon.