The Art of Fugue, or The Art of the Fugue, BWV 1080, is an incomplete musical work of unspecified instrumentation by Johann Sebastian Bach. Written in the last decade of his life, The Art of Fugue is the culmination of Bach's experimentation with monothematic instrumental works.

An unfinished creative work is a painting, novel, musical composition, or other creative work, that has not been brought to a completed state. Its creator may have chosen not to finish it, or may have been prevented from doing so by circumstances beyond their control, such as death. Such pieces are often the subject of speculation as to what the finished piece would have been like had the creator completed the work. Sometimes artworks are finished by others and released posthumously. Unfinished works have had profound influences on their genres and have inspired others in their own projects. The term can also refer to ongoing work which could eventually be finished and is distinguishable from "incomplete work", which can be a work that was finished but is no longer in its complete form.