Extracting music from "GameBoy Advance" ROM files can be a simple process if the ROM is using the "Sappy" music format. Fortunately, most of the GBA games use Sappy when it comes to their music files. A program called "Saptapper" is able to extract the Sappy music file from the ROM and save it to your computer's hard drive. The recent versions of this program allow the process to be automated. The only problem you will have are ROMs that use other sound drivers. At this time, there is no way to extract them.
Navigate to the Saptapper download page.
Right-click on the downloaded zip file and select "Extract Here" from the menu.
Click "Start" and type "cmd" in the text window. Press "Enter."
Navigate to the folder with "saptapper.exe" and your GBA ROM by typing "cd /(folder name)."
Type "saptapper (GBA ROM name)" to extract the music from the ROM.
GameBoy Advance ROMs are only legal to store on your computer if you own an original copy of the game.