A Secure Digital (SD) disc is a small chip that is used as a storage device, and can be inserted into any device that supports SD discs. As a backup for your iPod music, you can transfer up to 32GB of music from your iPod to your SD disc by connecting your iPod to your computer for synchronisation and inserting the SD disc into your computer. Once the music is successfully transferred, store the SD disc in a safe place to prevent damage, as the disc is fragile.
Insert the SD disc into your PC's SD slot, or into the SD card reader on your Macintosh computer.
Plug the USB cable into your iPod, and plug the other end of the cable into the USB port on your computer.
Click "Start," "All Programs," "Apple" and "iTunes" to start iTunes on your PC, or click the "iTunes" icon on the dock of your Macintosh computer.
Click "File" at the top of the menu and select "Transfer Purchased Music from iPod."
Open your iTunes Music folder in Finder (on Macs) or Windows Explorer (on PCs) to locate the recently-transferred music.
Drag-and-drop the files to the SD card icon in the Finder or Windows Explorer sidebar.
Right-click the SD card icon, and select "Eject" from the pop-up menu to safely disconnect after the files have transferred.