If I cancel my Apple Music subscription, what happens to my iTunes library that I had before signing up for Apple Music?

An Apple Music subscription supposedly does not interfere with your local library. However, users who find (or think they have found) that Apple Music messed up their local library have become a common feature on this Forum.

Here is an example from today:

all my downloaded music was stolen from a… - Apple Community

Therefore, make a backup of your current local library before you start the subscription!

Ideally all of your own media would be stored locally, and backed up to an external drive, along with a copy of the library database, before you get started with Apple Music. That way if you decide to offload your local files for reasons of space, or to gain access to the higher quality versions in Apple Music, you can always revert to your original library when you decide to stop using Apple Music. Apple Music and iTunes Match should be treated as library syncing services, not a backup.

tt2