Patent ID: 7386479

Claim:
A content sales server connected to electronic musical apparatuses over a communication network that allows communication among each other, comprising: a storage unit for storing a content database of a plurality of content items and an owned content list comprising owned content information describing content items owned by at least one user of an electronic musical apparatus, said owned content list associated with a user ID communicated from the electronic musical apparatus to the content sales site over the communication network; a processing unit adapted to search the plurality of content items stored in said content database for offerable content items in response to a request from said electronic musical apparatus, retrieve offerable content information describing the content items fulfilling the request and generate an offerable content list comprising the retrieved offerable content information describing offerable content items; refer to said owned content list specified by the user ID to detect offerable content information which describe the content items owned by the user of the electronic musical apparatus from among said offerable content list; and add owned information to the detected offerable content information to generate display data for displaying an offerable content list indicating which content items have been already owned by the user; and a transmitting unit for transmitting the generated display data to the electronic musical apparatus, wherein the processing unit is further adapted to notify the user of the electronic musical apparatus to confirm an order for a content item if the content item is owned by the user; distribute a content item to the electronic musical apparatus through the communication network in response to a request based on the offerable content list indicating which content items have been already owned by the user; and to update the owned content list stored in the storage unit in response to the distribution of the content item to the electronic musical apparatus wherein one or more content items are stored in and utilized by the electronic musical apparatus.