If we want to study about the life and legacy of person who contributed tremendously to the Thai music circle, there would be no doubt the person worth for this purpose is Rewat Buddhinan. The aims of this thesis are twofold. First is to study the life and legacy of Rewat Buddhinan. Second, which is more important, is to study the role he played in the Thai music profession and his influences on Thai music, with the emphasis on Thai popular music. Historical approach was employed as a major method of the study. Results from our study indicate that Rewat Buddhinan is a person in the Thai music circle that played an important role both on screen (front state) and behind the scene (back stage). In addition, Rewat also played a vital role in the Thai music business. His outstanding recognition, which is well accepted, is that he is a person who made a big change in the Thai music world. As a consequence of this change, the Thai music business has been developed and upgraded to be universal in terms of both music substance and music business which has been well-recognized by general public. The change also made Thai popular songs a full-scale music industry and this is the starting point of the new era for the Thai popular music industry.