I've tried everything and googled this but I cant seem to get the music to show up on my 3DS. I have a Windows 7 just in case you were wondering what I was using.

Anybody?

How dont you know? It tells you how to when you use 3ds sound...
Or is it that you followed the instructions and it didnt work?

Put SD card in slot
Make folders
Put songs inside folders

I followed the instructions here:
http://ca.answers.yahoo.com/question/index?qid=20110327051203...
Not sure, maybe you have another problem? It sure isn't Windows 7 causing it.
(Also, just a tip but only put 100 songs in a folder, if you put more they won't show up.)

I believe there is a certain file type I have to have the songs on. Which one?

DCIM most likely.

Alright, I swear I tried this before but I might be wrong. Thanks for the help.

No problem. Best of luck, buddy.

If you have followed directions for adding songs but nothing shows up, or only part of them do, it may be how you put them on--like in the file names, or too many items for the DS to deal with. I just fixed my son's.....
Regular directions.....
1) Put SD card in computer
2) Create Music folder
3) Create sublevel of folders by categories like artist
4) Put songs in folders (3DS takes several file types including MP3)
What they don't tell you.....
5) NO MORE THAN 100 ITEMS IN THAT MUSIC FOLDER (either songs or folders)
6) NO MORE THAN 100 SONGS IN EACH SUBLEVEL FOLDER (I'm not sure of the exact limit of total songs--I was dealing with about 200)
7) NO SPECIAL CHARACTERS IN SONG NAMES LIKE .-,'"() ONLY LETTERS AND NUMBERS AND KEEP SONG NAMES SHORTER RATHER THAN LONGER
I just spent 2 hours cleaning up all the songs and folders on my son's 3DS because he could only see a handful out of 200 songs. I saw conflicting information about how many items, but 100 seemed to be a common number. Also, Dad had included a lot of special characters that I thought may be causing the DS to ignore it. So I decided to simplify and stick with <100 and simplify file names.
AND IT WO9RKED!! NOW HE CAN SEE ALL OF THEM!!

Pretty sure 3DS sound supports MP3's.