ROM Hack Changing in game music

[Drake]

So I haven't tested it out cause I don't currently have my 3DS but I know that some games can be easily modified. My question is, can I dump the game and replace the music given with my own? What I want to do it for is New Leaf and replace all the day music for City Folk music. Sorry if this is already answered.

 

[adrifcastr]

http://gbatemp.net/threads/tutorial-how-to-decrypt-extract-rebuild-a-cia.388677/

 

[Bedel]

Some games use midi music files as 2048, what sucks.
I wish all games used some other format.