CNET speculates Google may be planning to launch an online music store:
The most recent evidence is adding "/music" to google.com's robots.txt file, meaning that such a subdirectory is expected to be created any time.
We also noticed this odd behavior earlier today. No "google.com/music" Web site exists on the public Internet. But searching Google's index for "google.com/music" yields a different result than the standard "Sorry, no information is available for the URL" error message.