This article focuses primarily on improvisation in the arts as discussed in philosophical aesthetics, supplemented with accounts of improvisational practice by arts theorists and educators. It begins with an overview of the term improvisation, first as it is used in general and then as it is used to describe particular products and practices in the individual arts. From here, questions and challenges that improvisation raises for the traditional work-of-art concept, the type-token distinction, and the appreciation and evaluation of the arts (...) will be explored. This article concludes with the suggestion that further research and discussion on improvisation in the arts is needed, particularly in the areas of non-jazz improvisation. (shrink)