In response to a request, one of primary content data as a copyrighted work and incidental content data is received from a server. With a music editing and sharing application, the content data is used in a secondary usage fashion for editing in order to produce new incidental content data. The incidental content data is not the one that is produced by arranging directly the primary content data as an editing material but play control information for giving an instruction defining a play mode. The incidental content data is uploaded to an incidental content server.