This dissertation describes a compositional model rooted in cross-influential methodology between complementary musical compositions that share generative source material. In their simultaneous construction, two composition pairs presented challenges that influenced and mediated the other's development with respect to timbre, transposition, pitch material, effects processing, and form. A working prototype first provides a model that is later developed. The first work Thema is for piano alone, and the companion piece Am3ht is for piano and live computer processing via the graphical programming environment Max/MSP. Compositional processes used in the prototype solidify the cross-influential model, demanding flexibility and a dialectic approach. Ideas set forth in the prototype are then explored through a second pair of compositions rooted in cross-influential methodology. The first work Lusmore is scored for solo contrabass and Max/MSP. The second composition Knockgrafton is scored for string orchestra. The flexibility of the cross-influential model is revealed more fully through a discussion of each work's musical development. The utility of the cross-influential compositional model is discussed, particularly within higher academia.

Soar! is a musical composition written for wind ensemble and computer music. The total duration of the work is approximately 10 minutes. Flocking behavior of migratory birds serves as the most prominent influence on the imagery and local structure of the composition. The cyclical nature of the birds' journey inspires palindromic designs in the temporal domain. Aesthetically, Soar! portrays the fluid shapes of the flocks with numerous grains in the sounds. This effect is achieved by giving individual parts high degree of independence, especially in regards to rhythm. Technically, Soar! explores various interactions among instrumental lines in a wind ensemble, constructs overarching symmetrical structures, and integrates a large ensemble with computer music. The conductor acts as the leader at several improvisational moments in Soar! The use of conductor-initiated musical events in the piece can be traced back through the historic lineage of aleatoric compositions since the middle of the twentieth century. [Score is on p. 54-92.]

This dissertation examines the role of noise in shaping the form of several recent musical compositions. This study demonstrates how the contrast of noisy sounds and harmonic sounds can impact the structure of compositions. Depending on context, however, the specific use and function of noise can vary substantially from one work to the next. The first portion of this paper describes methods for quantifying noise content using FFT analysis procedures. A number of tests on instrumental and synthetic sound sources are described in order to demonstrate how the analysis system may react to certain sounds. The second part of this document consists of several analyses of whole musical works. Works for acoustic instruments are examined first, followed by works for electronic media. During these analyses, it becomes clear that while the use of noise in each work is based largely upon context, some common patterns do exist across different works. The final portion of the paper examines an original work which was written with the function of noise specifically in mind. The original work is put through the same analysis procedures as works seen earlier in the paper, and some conclusions are drawn regarding both the possibilities and limitations of …