In Japan, this new year's, you could hear all of Beethoven's symphonies at one concert, to celebrate the coming of a new year. I've often thought of planning listening for a day along some crazy path like this... listen to one particular work (say, one complete Bach violin sonata), on repeat the whole day. I remember when I was still a teenager, I tried listening to all of Bach's Goldberg Variations on very low volume, to sleep by. It didn't work, I had to turn it off.