Download the Audacity software from its website.
Install Audacity by double-clicking on the application icon.
Start the Audacity program by clicking on the installed icon.
Drag the music file into the main window of Audacity. This will copy the file to the program.
Find the "Effect" menu at the top of the screen. Open the menu and click on "Reverse." The audio program will automatically reverse the entire song.
Go to the "File" menu and select the "Export" option. Click "OK" and listen to your new file after it finishes saving.