GarageBand for Mac: Use the Media Browser
The Media Browser makes it easy to browse, preview, and add media files to a project. Use the Media Browser to find and import songs from your iTunes library and movies from your Movies folder. You can also search for media files by name.
Open the Media Browser
Do one of the following:
Click the Media Browser button in the control bar.
Choose View > Show Media Browser (or press F).
Import media files
In the Media Browser, click Audio or Movies, depending on the type of media you want to import.
Select the location or folder that contains the files you want to import.
Click the Play button at the bottom of the Media Browser to play songs from iTunes or preview movies from your Movies folder before you import them.
Drag the files you want to import into the Tracks area.
Search for media files by name
In the Media Browser, click Audio or Movies, depending on the type of media you want to search for.
Enter a search term in the search field, then press Return.
To sort the search results, click any of the column headers.
Click the small “x” at the right side of the search field to clear the search term.