Music app taking extra storage when importing local files

Hello mounir000,

Thanks for choosing the Apple Support Communities. We understand you are wondering why you have 300GB more in storage on your Mac after importing your music library to Apple Music. We can help provide some clarity on this.

Have you double-checked your settings as shown below yet? This could account for what you're seeing. Change where your music files are stored on Mac:

"Consolidate your files in the Music folder

Depending on how you imported items into Music, some items in your library might be stored in different locations (for example, in another folder or on another storage device).

You can consolidate all the files in your library in the Music folder—for example, to make it easier to move your library to a new computer.

1. In the Music app  on your Mac, choose File > Library > Organize Library.
2. Select “Consolidate files.”
3. Files remain in their original locations, and copies are placed in the default folder."

"Add files to your library but not to your Music folder

When you add an item already on your computer to your library, Music places a copy of the file in your Music folder. The original file remains in its current location.

You can change this setting so that files are added to your library without being added to the Music folder. You might want to do this, for example, if you prefer to store files on an external disk but still want to view them in Music.

1. In the Music app  on your Mac, choose Music > Settings, then click Files.
2. Deselect the checkbox next to “Copy files to Music Media folder when adding to library.”

From now on, when you drag a file to your library, the item appears in Music, but the actual file isn’t copied or moved."

These settings may explain what you're seeing. If that does not appear to cover it, we recommend using this link to reach us for further assistance: Get Support

We hope this helps.

Cheers!