I've been using playlists to help expand my horizons - some of them found, most of them built myself (which is very easy to do). Some examples:
- 1000 Recordings to Hear Before You Die - This is based is based on Tom Moon's excellent book. I found one playlist (821 selected songs from most works in the list) and I started my own (complete albums, but only about 1200 songs so far).
- Rolling Stone Magazine's 500 Greatest Albums - I found this playlist with 6300 songs.
- Everybody's Dummy - This is one of my favorite album review blogs, with a lot of classic rock that I enjoy, as well as a lot of cool discoveries, so I made a playlist of his highly rated albums "4.5+ on Everybody's Dummy."
- Voyager Golden Record - Inspired by the great new Cosmos series on Fox, I just started a playlist of sounds and music from the Voyager Interstellar Record, a gold data disc that is attached to each of the two Voyager spacecraft that have just recently crossed the solar system's outer boundary. I also bought the Kindle version of Murmurs of Earth, a book written by Carl Sagan, Ann Druyan, and others about the creation of the Voyager Interstellar Record (the disc also includes a large number of images).