Volume 9, Number 4, October 2003
Copyright � 2003 Society for Music Theory
 MTO volume 9.4 presents two articles on aspects of transformational theory, each supported with imaginative illustrations rendered in innovative graphic formats. Richard Cohn models parsimonious and transpositionally combinatorial relations among tetrachordal set-classes through three-dimensional graphic renderings in his article, "A Tetrahedral Graph of Voice-Leading Space." Readers can explore the four triangular faces of the tetrahedron in Cohn's Figure 10, a movable 3-D image in QuickTime VR format.
 In "Square Dance Moves and Twelve-Tone Operators: Isomorphisms and New Transformational Models," Nancy Rogers and Michael Buchler use moving diagrams in animated GIF format to illustrate analogies between the cyclic patterns of square dancing and pitch transformation in atonal music.
 We have prepared these articles in Adobe PDF format in order to better accommodate mathematical equations and figures. The pages "with frames" are optimized for viewing with a web browser. For readers that prefer to save the PDF files to disk, versions "without frames" are also provided. These files are intended to be read with the Adobe Acrobat application and include html links in the text for accessing figures and examples. Also provided in the issue are listings of recently completed dissertations, job opportunities, and general announcements.
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