Hello gbatemp this is a simple tut for those who are stuck or don't know where to begin. This will allow you to make the file necessary to play music in your themes that you have made or are using on your 3DS. Requirements: An MP3 To Use - https://www.mediafire.com/?1vbipgyu7y3jw35 [Example] A way to convert MP3's to the WAV format [I use dbpoweramp] BRSTM Converter 3.4.1 - http://www.lakora.us/brawl/brstm/ BRSTM2BCSTM - http://www.mediafire.com/download/a3oc4deshm7srs7/BRSTM2BCSTM.rar Rules: The WAV file should be at a minimum 22.050 kHz, 16 Bit in quality and have stereo sound [This is a standard to prevent garbled sound] The max file size of the bcstm must be 3.371.008 bytes (or 3.3MB) Ok lets get started 1) Convert your MP3 to the WAV format using a converter of your choosing (Your WAV can be above 3.3 MB as it will be compressed once converted in the next step) 2) Run BRSTM Converter C# and select tools -> Simple WAV and select your WAV file 3) At the bottom left you can select if you want this file too loop while your 3DS is open [Optional] and hit ok 4) Click the OK button to the right and once again select the WAV File this will dump a .brstm file into BRSTM Converter 3.4.1\output if the file is above 3.371.008 bytes (or 3.3MB) try to shorten it using a program or a site like http://mp3cut.net/ and recreate your WAV file with the above steps. 5) Now Run BRSTM2BCSTM.exe and select the brstm file you just created this will automatically create a file with the same name but with the extension of bcstm. 6) Rename this file to BGM.bcstm and place it into ?:\3ds\3ds_homemenu_extdatatool Heres a picture if your confused - 7) On your 3DS Run The Ninjhax exploit created by smealum and run 3ds_homemenu_extdatatool which can be found here https://github.com/yellows8/3ds_homemenu_extdatatool/releases Select with the A button "Enable persistent theme-cache" then select "Copy theme-data from sd to extdata" and exit the app with the B button. 8) now just hit Select+Start too reboot your console and thats it your done! Question- Im not hearing anything what did I do wrong? Answer - Make sure you have Background Music checked for your theme in the Theme Editor. If theres anything in here that breaks any rules MODS please fix it and not remove the tut ill add Credits and a video tutorial late on.