The music that you download as part of your Xbox Music subscription fee would refuse to play somewhere within 30 days of your subscription having lapsed. Any music that you purchase the rights to own (which is over and above the subscription cost) is yours to keep. The former cannot be burned to a CD, etc.; the latter could be.
Originally Posted by ikissfutebol
By default, music downloaded to your computer from Xbox Music *will* display on your phone and will be available for streaming. You can prevent this from happening (most easily) by disabling the "Cloud Collection" feature on your phone.
2. If I download something on my computer, will it automatically appear on my phone for streaming? Is there a way to block this as a means of preventing data usage? *I know some things I bought with Zune seem to appear on my phone and I'm unable to delete them. Since I don't use playlists and just set things on shuffle, this could be potentially terrible for me*
I may be mistaken on this one (hopefully someone else will chime in!) but I do believe that unless you currently own an Xbox Live Gold Family Pack undergoing conversion, both of you would need your own Xbox Live Gold accounts in order to use the full feature set of Xbox Games on your phones. Without it, you would lose only the ability to send messages to other players via the Games hub. Note that Xbox Music is not included in the price of Xbox Live Gold...if Xbox Music is the service you had intended to ask about, you would lose the ability to stream/download full songs from that catalog should you forgo the subscription (though you can still purchase music from the phone and sync music that you own into the Music app).
3. If my Xbox Live Gold membership is registered to my account, but my wife would likely be the one who has the account in her name, what features would go missing? Are these going to change at all with the upcoming changes to Xbox Live Gold memberships?
There are no limits to the number of songs you can download (from Microsoft: "With an Xbox Music Pass, you can download, stream, and listen to as many songs from the Xbox Music store as you want as often as you want."). However, you are limited in the number of devices you can download to: no more than 4 different devices.
4. Is there a limit to the number of songs I can download over the life of a membership? I thought I had read in an old thread about 1000 or something?
Hope that helps!