The Internet, revolution referred to as the greatest media medium revolution since the discovery of the printing technology, discovery of typography has given birth to various legal issues in the field of intellectual property rights. Specifically, regulating the usagerelationship between copyright holders and users of their contents has recently been the focus central theme in copyright legislative regime. This article thesis places a focus on the interpretation of the rights of and their usage the relationship between copyright holders and content users in light of the recent technological developments in the copyright legislative regime relating to the music industry, and provides the author's perspective on resulting from the change of technologies in the copyright legislative system, particularly, related to the music industry, the issues that emerged from the music industry and on study of problems in view of business-people over the many years during which the author had worked with leading communications companies, Internet companies, electronic appliance manufacturers, and content providers in Korea. Also, this article thesis also reviews has studied the main issues that emerged from the Soribada case, the largest dispute in the on-line music industry, in which the author was personally involved as legal counsel to the Soribada system operator. Soribada case which was the largest issue in the field of on-line music industry and as a legal working staff on the legal execution process and the content of refutation thereof, so as to catch the core of the refutation. This article thesis is divided into three parts - (1) Part One examines the on-line music industry by looking at its characteristics and possible effects on that is, the contemplation of the on-line music industry about features of the on-line music industry and about what effects the on-line music industry causes to other content markets in the future (2) Part Two discusses various legal issues arising in that the on-line music industry raised, including those related to (i) the right to reproduction, (ii) the right of transmission, (iii) the liabilities responsibility of service providers, (iv) private use, (v) contributory infringement, aiding and abetting and (vi) technological developments of technologies and program production; and (3) Part Three provides the analysis of the Soribada case and the Bugs Music case, which are two representative the P2P case and the streaming cases, and the author's opinion on the legal issues in the on-line music industry which emerged from the aforementioned cases.