I am being billed for music I did not purchase

Where are you seeing these 'bills' ? iTunes account's purchase history (including family members accounts if you are a family organiser in family sharing) : See your purchase history in the iTunes Store on a Mac or PC - Apple Support ? Email / phishing email ?

If it shows on your iTunes account but you didn't buy it, and if nobody else has access to the account and did it, change the account's password if you haven't already done so (What to do after you change your Apple ID email address or password - Apple Support) and contact iTunes Support : http://reportaproblem.apple.com or https://www.apple.com/emea/support/itunes/contact.html

If it doesn’t show on your account(s) (and if it's not a phishing email nor : About payment card authorization holds in the iTunes Store - Apple Support) contact the card issuer