This invention relates to the method and system of producing/composing user's own music (musical composition, arrangement, and performance) on the web site. The system creates musical patterns out of all kinds of music, recommends the ideal patterns in accordance with genres selected by users, and ultimately enables ordinary internet users without musical knowledge to compose their own music simply by selecting and assembling the patterns. The system of invention is composed of a DB server including a music database storing a music data specifically patterned from a plurality of music and a lyrics database storing lyrics data patterned from a plurality of lyrics and various kinds of texts; an user PC for downloading the music and lyrics data through a music file real-time player; a web site; and a music pattern automatic control server for controlling the files suitable for music by allowing the user to select and combine the patterned music and lyrics data of the said DB server in accordance with acoustics and harmonics.