This paper presents CounterChoice, a mixed-initiative creative application which creates a first-species counterpoint composition together with its user. The user provides the first voice, the cantus firmus, through a graphical interface provided as a web application, and CounterChoice generates the counterpoint voice using a logic program written in the finite-choice logic programming language Dusa. The resulting composition is presented both as playable audio and as Dusa code, at which point the user may continue to edit and revise via the same interaction loop.

The CounterChoice experiment serves as both a demonstrator application for the Dusa language and a case-study in the development of domain-specific interfaces for modern logic programming languages, so that creators in those domains may access the full potential of such languages for procedural content generation and exploratory play. We present findings on the suitability of Dusa for encoding the formal rules of counterpoint, the impact of Dusa on the frontend interface, and generalizable design recommendations for developers of logic programming languages with similar applications to Dusa.