The traditional rules of voice-leading in Western music are explicated using experimentally established perceptual principles. Six core principles are shown to account for the majority of voice-leading rules given in historical and contemporary music theory tracts. These principles are treated in a manner akin to axioms in a formal system from which the traditional rules of voice-leading are derived. Nontraditional rules arising from the derivation are shown to predict formerly unnoticed aspects of voice-leading practice. In addition to the core perceptual principles, several auxiliary principles are described. These auxiliary principles are occasionally linked to voice-leading practice and may be regarded as compositional “options ” that shape the music-making in perceptually unique ways. It is suggested that these auxiliary principles distinguish different types of part writing, such as polyphony, homophony, and close harmony. A theory is proposed to account for the aesthetic origin of voiceleading practices.

Music today is more ubiquitous, accessible, and democratized than ever. Thanks to technologies such as high-end home studios, audio compression, and digital distribution, music now surrounds us in everyday life, almost every piece of music is a few minutes of download away, and almost any western musician, novice or expert, can compose, perform and distribute their music directly to their listeners from their home studios. But at the same time these technologies lead to some concerning social effects on the culture of consuming and creating music. Although music is available for more people, in more locations, and for longer periods of time, most listeners experience it in an incidental, unengaged, or utilitarian manner. On the creation side, home studios promote private and isolated practice of music making where hardly any musical instruments or even musicians are needed, and where the value of live

ensemble of fifteen laptop-based meta-instruments, began its first season. In this article, the author explores the motivations for starting a laptop orchestra, both in musical and cultural terms, and some of the aesthetic, technical, and compositional issues that face those interested in working with such an ensemble. 1. LAPTOPS AND ORCHESTRAS That the notion of a ‘laptop orchestra ’ is seemingly paradoxical is one of my prime motivations for creating one; the pairing of these two inventions is perhaps obvious only because of its apparent impossibility. One is an almost archaic institution whose continued existence is something of a miracle, the other a technological newcomer that has become commonplace and seems likely to be with us, at least in some form, for