The classification of Western art music is a complex area of knowledge organization, yet the reasons for those complexities have not been fully studied. This article dissects the concept of orthogonality, in particular regard to music classification. Orthogonality (antonym: dependency) means that one facet acts independently from another facet. While orthogonality is an assumed quality of facets, it has attracted relatively little attention in knowledge organization discourse. This article utilizes bibliographic classification schemes, musicological writings, and musical works, to analyse orthogonality in music classification. The relationships between the medium, form/genre and function facets are unpicked and a strong dependency is found between these facets. Whether this orthogonality exists as a construct of faceted classification or stems from the domain knowledge is explored. Furthermore, the analysis initiates new thinking about the general concept of orthogonality. The idea of a spectrum of dependency is proposed. In addition, novel, orthogonality-derived phenomena are discussed – “dynamic facets” and “meta-dependency” – where the boundary between what is and is not a facet are blurred. The concluding model visualizes the chain of dependencies between music facets, ultimately showing how the lack of orthogonality plays a key role in the complexity and issues found in music classification.

中文翻译：

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正交性、依赖性和音乐：探索音乐方面之间的关系

西方艺术音乐的分类是一个复杂的知识组织领域，但其原因尚未得到充分研究。本文剖析了正交性的概念，特别是在音乐分类方面。正交性（反义词：依赖）意味着一个方面独立于另一个方面。虽然正交性是一个假定的方面质量，但它在知识组织讨论中引起的关注相对较少。本文利用书目分类方案、音乐学著作和音乐作品来分析音乐分类中的正交性。媒介、形式/流派和功能方面之间的关系没有被挑选出来，并且在这些方面之间发现了很强的依赖性。探讨了这种正交性是作为分面分类的构造存在还是源于领域知识。此外，该分析引发了对正交性一般概念的新思考。提出了依赖范围的想法。此外，还讨论了新颖的、正交性衍生的现象——“动态方面”和“元依赖”——其中什么是和不是方面之间的界限是模糊的。结论模型将音乐方面之间的依赖链可视化，最终展示了缺乏正交性如何在音乐分类中发现的复杂性和问题中发挥关键作用。讨论了正交性衍生的现象——“动态方面”和“元依赖”——其中什么是和不是方面之间的界限是模糊的。结论模型将音乐方面之间的依赖链可视化，最终展示了缺乏正交性如何在音乐分类中发现的复杂性和问题中发挥关键作用。讨论了正交性衍生的现象——“动态方面”和“元依赖”——其中什么是和不是方面之间的界限是模糊的。结论模型将音乐方面之间的依赖链可视化，最终展示了缺乏正交性如何在音乐分类中发现的复杂性和问题中发挥关键作用。