Now what is artistic, aesthetic, about a work which is a body of concepts? This question can best be answered by telling where concept art came from; I developed it in an attempt to straighten out certain traditional activities generally regarded as aesthetic. The first of these is "structure art," music, visual art, a.s.f., in which the important thing is "structure." My definitive discussion of structure art can be found in "General Aesthetics"; here I will just summarize that discussion. Much structure art is a vestige of the time when for ex. music was believed to be knowledge, a science which had important things to say in astronomy a.s.f. Contemporary structure artists, on the other hand, tend to claim the kind of cognitive value for their art that conventional contemporary mathematicians claim for mathematics. Modern examples of structure art are the fugue and total serial music. These examples illustrate the important division of structure art into two kinds according to how the structure is