Unique representation, such as music or image full of originality, is generated in relation to a specific data sequence such as a telephone number.A music generation server 10 is provided with a material table TA in which material data associated with music phrases are provided in correspondence with the digits of the telephone number and the numerals thereof given at the respective digits, and such server is connected to a user's terminal, such as a PC 50 or a cellular phone 56. When a specific data acquisition program 30 is executed to acquire a telephone number as a specific data sequence from a user, a material data extraction program 32 is executed to make reference to the foregoing material table TA and extract therefrom a particular material data MD corresponding to the acquired telephone number. Then, a generation program 34 is executed to arrange such material data MD in a predetermined order and thereby generate one completed piece of music. A data of so generated music is transferred or transmitted by a transfer program 42 to the user's terminal through an Internet 70, and then reproduced as a melody of incoming call to be ringed in the cellular phone for example.