The present study develops a dynamic model of strict and free composition that views them as relative to a specific historical context. The dynamic view espoused here regards free embellishments of an earlier compositional generation as becoming the models for a strict compositional theory in a later one. From the newly established strict compositional models, succeeding generations of composers produce new free embellishments. The first part of the study develops the dynamic conception of a continuously emerging strict composition as the context necessary for understanding Anton Bruckner's compositional methodology with respect to the harmonic instruction of his teacher, Simon Sechter. In other words, I view Sechter's harmonic theories as a strict compositional platform for Bruckner's free compositional applications. Many theoretical treatises of the seventeenth, eighteenth and nineteenth centuries such as those by Christoph Bernhard, Johann Philipp Kirnberger and Sechter acknowledged that strict composition must provide the structural framework for free composition. The above procedure becomes a manner of justifying a free embellishment since a "theorist" can demonstrate or assert the steps necessary to connect it with an accepted model from a contrapuntal or harmonic theory. The present study demonstrates that the justification relationship is a necessary component for understanding any theory as a strict/free one. By examining Sechter as a strict methodology for Bruckner, we can view the free applications that the latter develops. Bruckner's own theoretical documents-the marginalia in his personal copy of Sechter's Die Grundsätze der musikalischen Komposition and his lecture notes, Vorlesungen über Harmonie und Kontrapunkt an der Universität Wien, taken by Ernst Schwanzara-provide extensions and elaborations to Sechter's theories. In addition, theorists sympathetic to Sechter's approach and Bruckner's personal students provide further material for understanding Bruckner's free application of Sechter's strict harmonic perspective. The study uses my own observations, as well as the extensions indicated above, to generate the transformations used by Bruckner to elaborate the Sechterian harmonic structure.