Task: Question Answering
Input (English): Context: Its revolutionary ideals no longer had any place . As a result people began to look inward . The music became far more introspective ( it is interesting to note that metal music went through a similar change , albeit about a decade later ) . Ones personal experiences and the way in which one was affected by the world , became the driving force of musical content . This introspection was to give birth to the Emo sub - genre . 
Question: What may be the reason for music evolution ?
Output (English): Because everything evolves and changes .