Overtone describes itself as an environment for creating "collaborative programmable music." It uses the Clojure programming language to control the SuperCollider audio synthesis software. The system is quite flexible and allows users to create software-defined music and sounds in a variety of ways. Compositions can be pre-programmed to simply play from beginning to end without user intervention. Overtone also allows users to create libraries of audio loops, which can be interactively invoked and even modified as they are playing. By writing code to specify the sound waves that should be generated, software-defined instruments can be created. Users can mix and match these and other approaches to taste, creating their own custom music creation environment. The Documentation section of the Overtone site contains installation instructions for Linux/BSD, macOS, and Windows computers. It also provides a brief tutorial and some reference information on the system. Additional examples along with more detailed reference material can be located on the Overtone Wiki.