How to Play MP3 Files on Your Nintendo 3DS

Did you know that the Nintendo 3DS can play music in MP3 and AAC format? Not only that, you can have a lot of fun playing around with your songs and other recordings in the Nintendo 3DS's music player. Want to give it a try? Follow these steps on how to play music on your 3DS.

What You Need

A Nintendo 3DS
An SD Card (one is included with the Nintendo 3DS)
Music files in MP3 and/or AAC format
A PC with an SD Card reader

Here's How

Make sure your Nintendo 3DS is turned off.
Remove the Nintendo 3DS's SD card from its slot. You can find the SD card slot on the left side of your 3DS. Open the covering for the SD card slot, and push in the SD card in order to free it. Pull it out.
Insert the SD card into a computer that contains the music files you want to transfer to your Nintendo 3DS. Your computer must have an SD card reader.
If a menu pops up asking what you'd like to do with the removable media you just inserted, you can click Open folders to view files. If the menu doesn't pop up, try clicking My Computer, and then click on whatever option you're offered for your removable media (usually labeled as Removable Disk.
In a separate window, open up the folder that contains the music you want to transfer. Copy and paste (or drag and drop) the music files that you want on your Nintendo 3DS onto the SD card. The data should go on the card itself: Do not put it in the folders marked "Nintendo 3DS" or "DCIM."
When the music has finished transferring, remove the SD card from your computer.
Insert the SD card, connectors-up, into your Nintendo 3DS. Make sure the power is off.
Turn on your Nintendo 3DS.
Tap the Music and Sound icon on the bottom menu screen.
Using the d-pad, press downwards until you reach the folder marked SDCARD. Press the A button to select your uploaded music from a menu.
Rock out!

Playlists and More

You can assign your Nintendo 3DS music to playlists. When you play a song, click the Add button on the bottom screen. Select a playlist, or make a new one.

You can have some fun manipulating your sound file. When a song is playing, tap the buttons on the bottom screen to change the song's speed and pitch. You can also filter it through a "Radio" option, remove the lyrics with the "Karaoke" option, add an Echo effect, and (this is the best) convert the song to an 8-bit chiptune. Use the L and R buttons to add more effects, including claps, snare drums, meowing, barking(!), and more.

"Pull" the rope on the bottom screen (or use the up and down buttons on the d-pad) to assign a different graphic to move to your audio output. There's a lot of retro love here, including a graphic that's reminiscent of a title from the Game & Watch series, and the little dudes from the NES classic Excite Bike.

If you close your Nintendo 3DS, the music will still play through your headphones.

When your Nintendo 3DS is open, click the right and left buttons on the d-pad to shuffle through your playlist.