Does Apple Music have storage?

My understanding is that if you use "Sync Library" with an Apple Music subscription, and then stop subscribing, "synced" copies of songs are deleted or stop working.

If songs are missing from your music library after you turn on Sync Library – Apple Support

"If you canceled your subscription to Apple Music or iTunes Match, your music library is removed on all of your devices except for the original computer where your music library is downloaded. Your iTunes purchases will remain in your Library on all devices. All music that you added or downloaded from the Apple Music catalog is removed. Any playlists added from the Apple Music catalog, created using music from the Apple Music catalog, or synced to a device using Sync Library are also removed."

So I wouldn't consider "Sync Library" to be a backup of any sort. Apple says the same thing.

"Apple Music isn't a backup service. Make sure to back up your music library before you make any changes."

As far as iCloud storage goes, subscribing to Apple Music or iCloud Match does not offer any extra iCloud storage for other stuff such as backups and photos synchronized through iCloud Photos. But I believe that cloud storage needed for the proper operation of an Apple Music or iCloud Match subscription is not counted against the regular iCloud or iCloud+ storage limit.

Hi,

Whilst you can match or upload music with an Apple Music subscription, you should not consider this as a backup.

You should keep a separate backup backup on an external drive.

Jim