Difference Between Downloading Music and Having itIn Library

If you are an Apple Music subscriber and you stop the subscription, only the not owned songs will disappears from your library (downloaded or not, it makes no difference).

When I say own I mean purchased (in iTunes Store as an album or single song, in other online stores, coming from a CD, etc.), not “rented” through a subscription. In this case you own them and you can download them whenever you want regardless of an active subscription.

I know, even the subscription is a purchase. The difference is that the content of a subscription is not yours forever. It'll last only until you keep the subscription active.

It's like buying a car – say, named A – by cash. It's yours. Forever. Then you add a subscription which lets you drive all the cars the dealer has in its shop (A, B, C, D). Car A is already yours so you don't care. You can find useful to drive B, C and D cars from time to time. When you stop the subscription you have to return the cars you don't own (B, C, D). Car A remains in your garage because is yours. If, during the subscription, you decided to buy car B (again, by cash) then it will stay with you even when the subscription ends.

Downloading in the example of cars would mean having them stored in your garage. You can store any car you want when the subscription is active. When it ends, only A and B can be stored, because you bought them in full price. The dealer knows you purchased them in their entire value so you are eligible to own them.

In your library you can store songs you own (e.g. ripped from a CD you bought or purchased in iTunes/elsewhere). They will always be yours. You can decide to keep the music purchased in iTunes downloaded or to download when needed.

If you are an Apple Music subscriber you can download locally any song available in Apple Music catalogue too, even if you don't own them. Moreover you can stream them and keep conveniently a copy of songs you own synced in iCloud. You're eligible to keep the songs you don't own offline until your subscription is active.

As soon as your subscription stops the downloaded songs disappear and you're not eligible to stream them anymore because you don't own them. The subscription is somehow similar to renting.

As a rule of thumb, if storage is not a problem, I suggest to keep always a copy of the music you own downloaded on your Mac. It's your musical archive. You never know what could happen in the future with any cloud service.

Hope it's a little more clear now.

To some extend it's true that you have unlimited access to the the whole music catalogue. The downside is that actually you never own the music and when the subscription ends everything not “fully purchased” vanish.

The same rules apply to other digital subscription services like Netflix, Spotify etc.

Another thing: subscriptions as a concept are nothing new. The problem with digital/modern subscriptions is that you get a lot in the present and nothing in the future.

I mean, a subscriber of a printed magazine can keep all the magazines he/she received even after the subscription ends. With modern content subscriptions that's not true anymore. When you stop paying you have to return everything back. The subscriber have access only to the magazines issued during his/her subscription, though, not the whole publisher catalogue.

There're pros and cons.

When you cancel your Apple Music subscription the music you downloaded will become greyed out and will not play for one month (30 days). If you re-activate the subscription during that 30 day period they will become active again. After 30 days the songs will disappear. The songs that you “fully purchased” will not be greyed out and will remain yours of course.

About the second question. On your Mac you need to activate iCloud Music Library in iTunes Preferences (it's a checkbox in the General section). On iOS devices you need to toggle iCloud Music Library in Settings -> Music.

Speaking about your second question: I don't think it's possible to sync the downloads, that is if I decide ti download a song on my Mac then it's automatically downloaded on my iPhone (if this was what you meant).

I'm glad I was able to help.