I have been reading about Apple Music removing original music from your computer
Do Not download Apple Music
Here is the original article. https://blog.vellumatlanta.com/2016/05/04/apple-st...
Funny enough, it now maybe user error http://www.imore.com/no-apple-music-not-deleting-t...
When you press delete on a song in your iTunes Library with Apple Music or iTunes Match enabled, you'll see the following dialog:

If you choose "Remove Download," it will send the local file from your hard drive to your Trash, but leave the reference in your library — so that you can stream that track directly from iCloud Music Library. It won't delete the file until you empty your Trash.
This is great if you're on a laptop and want streaming access to your music library, but you don't want the hassle of having 40GB of music on your hard drive. But it should only ever be done on a secondary computer or secondary iTunes Library— never for your master library.