One of my hobbies is classical music. Over the years, I've imported my library into iTunes and included composition date in the info. Now I am able to sort my 8.7 days worth of classical music by composition date, and I've listened straight through (takes 3-6 months) twice, now.
Listening this way really tunes your senses to the western canon of music, and it really strikes you when a new development comes along. Suddenly the music you've been listening to for the last week changes. This time through, I'm up to Wagner and Tristan and Isolde's Overture was WAY different than the Chopin, Liszt and Dvorak I'd been listening to. A deeper study of Wagner and this opera reveals some disturbing elements, but on the surface, the musical change is fascinating.