Abstract Music engravers nowadays use music notation software to create scores for musical works. As is common in any creative process, many different versions of digital artifacts are created—e.g., to manage editions of the same musical work, editorial markups, or the history and genesis of compositions. In the field of software engineering, researchers have proposed the use of features, i.e., user-visible aspects of systems, to manage both revisions and variants of source code and other software artifacts. Feature-based version control systems establish and maintain feature-to-code mappings defining which parts of the artifacts realize particular features, e.g., which code implements a specific function. These mappings can then be used to generate new variants based on the artifacts by selecting the desired features. Our article provides an in-depth study on feature-based version control for music notation. Our automated approach adopts the domain-specific language (DSL) LilyPond and the feature-oriented version control system ECCO. Existing studies show that features in musical scores are often fine-grained and affect only small parts of an artifact, are scattered across noncontiguous locations in the artifact, and highly interact with each other. Such properties have strong implications for the usefulness of versioning tools. Our experiment investigates two factors related to the correctness of output from feature-based version control systems when used for symbolic music notation. We demonstrate the incremental refinement of feature-to-artifact mappings when committing DSL code. We further study the impact of the order of feature interactions on the correctness of the automatically generated music artifacts. We find that a larger feature interaction threshold produces only marginally more correct results, but fixing and recommitting incorrect variants has a more powerful effect. Our results further show that considering DSL specifics is important for versioning fine-grained and scattered features.
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