A plurality of client apparatus are individually connectable to a server apparatus via a communication network at any desired time. The server apparatus automatically selects suitable performance information from its own database, and delivers the thus-selected performance information to each of the client apparatus currently connected to the server apparatus. User of each of the client apparatus can request a desired music piece from the server apparatus. The user-requested music piece is selected by the server apparatus in accordance with a predetermined priority order and interleaved or incorporated between the automatically-selected music pieces, so that the incorporated user-requested music piece is delivered to the client apparatus along with the automatically-selected music pieces. In requesting a desired music piece, the user can impart the music piece with additional information such as desired texts and images. The additional information is delivered to the client apparatus along with the performance information of the user-requested music piece.