Thanks everyone for your replies. In the end, Bruce's link proved most helpful as it showed me how to access my music, once it was added. I also appreciate controlav confirming that I can't sign in. So now I know I should stop trying. Cheers
Thanks Bruce I've already added the music service. My problem is in adding the voice service. The existing voice service is registered under my wife, and I have no ability to sign in unless I do so under her account, which I don't want to do.