How does Samsung GT-I9300 turn songs into ringtones?

Sorry, there is a folder named "Ringtones" in the root directory of your mobile phone storage. This is the ringtone of your mobile phone. You can see your songs in the sound settings. There is also a folder called "Notice", which is the folder of SMS ringtones. When you put a song into it, you can choose your favorite SMS ringtone in the sound settings.