Things You'll Need
Instructions
Turn on your computer. Install iTunes if you do not have it installed on your computer already. iTunes can be downloaded for free from apple.com/itunes. Open iTunes on your computer. Click on the tab at the left side of the screen labeled "My Library." This will bring up all of the music in your iTunes music folder.
Right-click on the song you would like to install on your DSi. Scroll down to the option labeled "Create AAC Version." Wait for iTunes to convert the song to .aac format, which is the necessary audio format for the Nintendo DSi.
Plug your Secure Digital memory card (SD card) to your computer. Wait for the SD card autoplay menu to open. Once this window opens, it will give you several options for your memory card. Click on the option labeled "Open folder to view files." You now have access to your SD memory card.
Right-click your mouse and scroll down to the option "New Folder." Create a folder and name it "DSi music folder."
Open your screen to your iTunes musical library. Right-click on the .aac version of the song you would like to install on your DSi. Choose the option labeled "Copy."
Navigate back to the folder you created named "DSi music folder." Paste the song you copied from iTunes to the DSi music folder."
Remove the SD card from your computer and plug it into your DSi. Turn on your DSi and choose the sound option from the music screen. Click on the option labeled "SD Card." This will bring up your folder you named "DSi music folder." Choose this folder and wait for the songs you added to the folder to load.