This submission consists of three parts, found in two volumes. Volume 1 consists of a folio of eight original compositions, composed during the tenure of my PhD candidature at the University of Adelaide. These works cover a range of media, including symphony orchestra with soloist, large chamber ensemble, string quartet with soprano solo, guitar quintet, mixed choir and vocal trio. Volume 2 presents an exegesis that contains commentary on the genesis and analysis of the submitted works, together with an explanation of certain modal processes that have been explored and applied. Volume 2 also contains three minor compositions that were composed during my candidature, presented as an Appendix. These are analysed and referenced within the exegesis discussion. Two CDs of live recordings of some of the submitted works are included as part of Volume 2. The Exegesis, Appendix and Sound Recordings found in Volume 2 act as secondary material to support the primary material presented in Volume 1. Of the eight compositions presented in Volume 1, Skin, Metal, Wood – Concerto for Percussion and Orchestra is the major orchestral work of over 30 minutes, in fulfilment of submission requirements. The musical works contained within this submission offer a personal exploration of certain modal processes. In particular, the tonal principles of modulation and key relationships have been transferred into a modal system that features church, folk and synthetic modes. The exploration of modal processes has been carried out through the works themselves, and the accompanying exegesis acts as a commentary on the genesis of the works. / Thesis (Ph.D.) - University of Adelaide, Elder Conservatorium of Music, 2008