Ownership & rights
Copyright vs Ownership
Copyright is the legal protection that arises automatically when music is created; ownership is the question of who currently holds that protection and can therefore authorise or forbid uses.
In practice
You never "buy copyright" as an abstract thing — you acquire the position of owner over an existing copyright, through a written assignment. Everything else, from a stock download to an enterprise licence, leaves the owner in place and just describes what you are permitted to do.
Real questions
Can copyright be transferred?
Yes. Economic rights can be assigned in writing. Moral rights, such as the right to be recognised as the author, cannot be assigned in many jurisdictions.
Does a licence make me the owner?
No. A licence is permission to use something you do not own, granted under conditions and often for a limited period.
How long does copyright last?
Typically the life of the author plus 70 years in the EU and the US, with variations by country and by type of right.
Registering something does not create ownership
Deposits, hashes and society registrations are evidence, not title. Title comes from creation or from a signed transfer.
Related terms
Own the track instead of renting it
Sonify Music sells exclusive buyouts of catalogue tracks: one payment, full ownership, the track removed from sale and a named certificate of ownership.