Transfer music to a different Apple ID
I have for historical reasons 2 Apple IDs:
A) firstname.lastname@icloud.com
B) firstname.lastname@mailprovider.com
I have an Apple Music subscription with B, but would now move it to A.
I have now made a subscription for A, but when I log out of B in Apple Music, and log in to A, I only see the titles which I had ripped from various sources (CDs, Youtube Videos, etc.), but not the ones that I had downloaded from Apple Music. How can I transfer those to my new ID?
MacBook Pro