Musical-score-related data set, including musical score information and right-to-use information defining a usable range of the musical score information, is distributed via a network or the like, and such a musical-score-related data set is stored in memory of an apparatus having received the data set. The right-to-use information includes information indicating that storage of the corresponding musical score is authorized or not authorized. When the musical score is to be displayed, the musical score information of the memory-stored musical-score-related data set is read out so that the musical score is visually displayed on a display device. When a musical score storage instruction or musical-score-display termination instruction is given by a user, a determination is made, on the basis of the right-to-use information of the memory-stored musical-score-related data set, whether storage of the musical score is authorized or not, and, if the storage of the musical score is not authorized, the corresponding musical score data set is deleted from the memory. The right-to-use information also includes information indicating that transmission of the corresponding musical score is authorized or not authorized, and, only when it is determined that the transmission is authorized, the transmission, to another apparatus, of the musical score is authorized.