This paper is one of the results of my ongoing diachronic investigations concerning the music of hereditary shamans on Chindo, an island in south-west Korea. My first field research on the music there was carried out in the early 1980s for a year; this work resulted in my dissertation (Park 1985). About twenty years after my first fieldwork, during the summers of 2000-2001, I made a number of trips back to Chindo, focussing on more specific issues, such as change, improvisation, and comparative analysis. A recent publication of mine (Park 2003) deals with the general nature of the changes the tradition has undergone. The present paper deals specifically with changes in improvisational practice.