As a former college professor who taught Copyright law in the business school of San Jose State University, I must remind this august group that when you purchase music or video on any pre-recorded media including digital downloads, you never really "own" the content. What you've purchased is the limited use rights to the content and if the media is physical, the piece of plastic containing the material. The owner of the copyright can, in theory anyway, revoke those use rights at any time.
It's just that they are far, far, far less likely to take that sort of action with a CD or LP or whatever you've purchased than they are with a streaming service or radio station. And with streaming services they are much more likely to force them to offer lower-quality versions if they are not happy with the royalty payments they are receiving, regardless of what you think you have "paid for."
OK, ass-like professor attitude put back in the box where it belongs.