An uploader transmits to a server a request start notification indicating
the start of a registration request and then transmits to the server a
plurality of registration requests for pieces of music piece data. Upon
receiving the plurality of registration requests from the uploader, the
server registers the pieces of music piece data in a database in an HDD.
After transmitting all the registration requests, the uploader transmits
to the server a request completion notification indicating the completion
of the registration requests. The server transmits an updating
notification to an audio client after receiving the request completion
notification. Therefore, traffic between the server and the client can be
reduced when the server updates the database.