Connect the device to a computer using the supplied USB cable.
From the computer, launch File Explorer or Windows Explorer or Finder.
For Windows Explorer, press the Windows+Ekeys (+E) using the computer keyboard.
For Finder, click the Finder icon located on the dock.
From File/Windows Explorer/Finder, click Windows Phone (under Portable Devices).
Create a new music folder or open the existing music folder (if present).
Utilize the computer to copy music and other audio files into the music folder.
For any accompanying artwork in JPEG format, rename the art file albumart.jpg and copy into the same folder as the music files.
To further organize files, create a subfolder in the newly created music folder and copy desired music files into it.