This one might be somewhat of a stretch as it seems that not many people are interested in 'old' music these days but I highly recommend a trip to the internet archive's 78 RPM collection.
If nothing else you will get to listen to some musical history. I recommend starting at the Al Jolson collection or with the novelty records from the collected works of Benny Bell (the song Shaving Cream is played on the Dr. Demento show quite frequently).
(You don't know what a 78 RPM is? It was the predecessor to the vinyl LP. You don't know what an LP is? Yikes...)