How to mount cifs share read-write?
Solution 1:
A CIFS mount cannot override the permissions settings of Samba or the underlying Linux permissions.
Your "music" share definition allows only "erik" access to the share. Since the Music subfolder - on the server - is likely owned by "erik" everything should work.
Except you stipulated force user = nobody in your share definition. That "forces" "erik" to become "nobody" which likely has no write access to that folder.
Either remove the force user = nobody line from your [music] share or change it to force user = erik
Then restart smbd