Import music from a computer to Music on Mac
In the Music app on your Mac, choose File > Add To Library or File > Import.
If you selected “Copy files to Music Media folder when adding to library” in Files preferences, you see File > Import.
Locate a file or folder, then click Open.
If you add a folder, all the files it contains are added to your library.
Tip: You can also drag a file or folder from the Finder to the Music window to import it.
By default, Music places a copy of each audio file in the Music folder (Home/Music/Music) and leaves the original file in the current location. For information about adding an alias to the file (instead of creating a copy), see Change where your music files are stored.
When you import an item by dragging it to the Music window or choosing File > Add To Library or File > Import, a reference (or “pointer”) to the item — not the item itself — is placed in the Music folder. You might not be able to play the song if you move it.