There’s been a lot written lately about Apple Music, iTunes Match, and the threat of one or the other deleting your music from your music library.

This issue has turned into a perfect storm of fear, uncertainty and doubt. At the end of the day, I believe an understanding of the basic mechanics at work here will make it easy to keep your music library 100% rock solid safe.

First, some background.

For starters, there’s iTunes Match, a service that puts all your music in the cloud, then makes that music available on all your devices.

In order to avoid storing five million copies of a particular track in the cloud, iTunes Match uses a combination of metadata (artist name, track name, etc.) and acoustic fingerprinting (the Shazam technique) to identify a track.

If your track is identified, the copy in the cloud is used instead of your local copy. If iTunes Match does not find a match in the iCloud Music Library, it uploads your copy to the cloud. Either way, the cloud copy of your track is then made available to all your other devices logged in with your AppleID.

A key point here is that the root of the tree here is the iTunes library on your Mac. You MUST start the iTunes Match process from a specific iTunes library. All the other devices will either merge the original Mac’s music with music already on the device, or replace existing music with that Mac’s music.

This is a critical point. Your music library starts life on your Mac, then is supplemented with music you buy elsewhere. As your devices sync, the tracks you buy elsewhere, make their way back to your Mac and are added to your original library. This scenario can get more complex if you have your root music library distributed across multiple Macs, but that is a topic for another day.

Here’s the key issue:

iTunes Match will never delete music from your Mac. NEVER.

So if you back up your Mac on a regular basis using Time Machine, your music is never in any danger.

Apple Music is a slightly different beast, but does follow the same prime directive. Back up your original iTunes Library, just as you would your photos. And never delete music from your Mac, unless you are absolutely certain you don’t want it any more.

To be clear, I am not saying the folks who report bugs with Apple Music and iTunes Match are wrong. I’m just saying that, assuming you’ve backed up your original iTunes Library, those bugs won’t cause you to lose music.

Put another way, I’m suggesting that anyone who lost music did so because they accidentally/inadvertently deleted the music themselves and didn’t have a backup.

One more point, then I’ll let you go. Kirk McElhearn wrote an excellent post on Friday pointing out a bug in the iTunes Match matching system. If you haven’t seen it, definitely do take a minute to read it through.

Here’s what Kirk did:

I changed its tags to Can’t Feel My Face, by The Weekend. (I picked this track because it’s one of the best selling tracks on the iTunes Store; I could have picked any track in the Apple Music catalog.)

Then he did this:

I waited for Apple Music to match the file, deleted my local copy, and then downloaded it from the cloud.

At the end of this process, Kirk’s original song was gone, replaced by Can’t Feel My Face.

Kirk did find a bug. Since Kirk had iTunes Match enabled, matching should have made use of acoustic fingerprinting, a la Shazam. iTunes Match should have detected Kirk’s ploy and returned the proper file. If you are interested in learning how iTunes Match and Apple Music do their matching, read this excellent post.

Unfortunately, many people saw this as Apple Music and iTunes Match deleting Kirk’s music. That did not happen. Apple didn’t delete Kirk’s music, Kirk did.

Here’s that last bit again:

I waited for Apple Music to match the file, deleted my local copy, and then downloaded it from the cloud.

Kirk deleted his local copy. Kirk’s post is absolutely valid and valuable, a real public service. He found a bug in Apple’s matching system, one that Apple needs to find and fix. But Kirk’s music was never in danger from Apple. And this is a key difference.

Back up your music. Make a second copy and keep it in a safe place (I actually have a backup of my music and photos in a safe deposit box, safe from fire). And don’t delete music from your Mac’s iTunes Library.