Yes, joining Yahoo! Music and Yahoo! is free. All you have to do to use Yahoo! Music is to join Yahoo!. Your Yahoo! ID will work on Yahoo! Music, so if you are already a Yahoo! member, you are all set.

To sign up for Yahoo!'s personalized services, follow the instructions for new users on the sign-in page of any of Yahoo!'s personalized services.

Note: Your Yahoo! ID cannot contain special characters or spaces. After you've signed up, you can use this same ID and password for all of Yahoo!'s services.