This should check for changes on the Billboard's Hot 100 and send an e-mail with the new music that appears each week.
I thought of this because I was no longer staying up to date with music, so I thought this might be useful to see what new popular music was coming out without having to constantly check for this.
Future Work:
Add support for Spotify and/or Google Music.
Maintain a blog somewhere with the changes.
Twitter feed that posts links to said blog.