This paper suggests a hypothesis that the fourth step appears after the three steps of Contents Industry Evolution Theory indicated by Kabashima (2009). The fourth step shows that the recording industry system has been formed and developed based on analogue sound recording technology, and that the system would change when digitization technology developes and becomes influential existence connecting with computers and ICT technology. The fourth step in recording industry evolution might have started at the late 1990's, when a few major companies re-integrate business functions and copyrights. On the other hand, comsumer has been able to upload and share the contents since the late 1990’s.
