Plural electronic musical instruments 2 obtain proficiency level related information, that includes items such as usage amounts of plural support functions which are used by a user in performing a playing practice of a practice piece during a period from a previous practice to the last practice and a proficiency level of a playing technique of a practice piece, and supply the information to a server 1. The server stores the received proficiency level related information in a database 14. Upon receipt of the information, a controlling unit 12 of the server 1 sends back the electronic musical instrument 2 information indicating the support function most suitable for practicing the practice piece determined on the basis of the received information and a series of information stored in the database containing the proficiency level related information including the item of the proficiency level corresponding to an aimed level.