Whenever we hear or read the term worldly music, we often think of metal rock bands, rock concerts, illegal drug use, alcoholism, etc. However, if we try to define worldly music, it simply means music that does not glorify or talk about God.
Under this definition, it would mean that even love songs, R&B, and even pop songs would be considered worldly as long as they promote the world system. This is an accurate definition and should be seen carefully. Any kind of music that aims to worship God is Christian, and all other music are worldly.
As a Christian, you should be particular in the music you listen to because what goes into your senses (eyes, ears, nose, taste, touch) have the possibility to influence you to sin. If the music you listen to promotes that you love yourself, and not God, then something’s wrong.