Abstract: A music data distribution system for distributing music data to an external device connected to a network, comprises: a storage device that stores first music data; a receiver that receives a music data distribution request from the external device connected to the network, the music data distribution request comprising at least music data identification information and music data quality information; a reading device that reads the first music data from said storage device in accordance with the music data identification information; a quality converter that converts the first music data into second music data having a quality different from the first music data in accordance with the music data quality information; and a transmitter that transmits the first or the second music data to the external device in accordance with contents of the music data distribution request.