This thesis represents the results of a theoretical and practical investigation of acoustic and electro-acoustic elements of Western music at the start of the twentyfirst
century, with specific attention to soundscapes. A commentary on the development of soundscapes is drawn from a multidisciplinary overview of concepts of time, followed by an examination of concepts of time in music. As a response to Jonathan Kramer's concept of `vertical' music (a characteristic aesthetic of which is an absence of conventional harmonic teleology), particular attention is paid to those theories of multiple nested temporalities which have been referred to by Kramer in support of non-teleological musical structures.
The survey suggests that new musical concepts, such as vertical music, have emerged from sensibilities resulting from the musical and associated styles of minimalism, and represent an ontological development of aesthetics characteristic of the twentieth century. An original contention of the debate is that innovations in the
practice of music as the result of technological developments have led to the possibility of defining a methodology of process in addition to auditive strategies,
resulting in a duality defined as 'tempomorphic'. Further observations are supplied, using findings derived from original creative practical research, to define
tempomorphic performance, which complete the contribution to knowledge offered by the investigation. Tempomorphism, therefore, is defined as a duality of process and audition: as auditive tool, tempomorphic analysis provides a listening strategy suited to harmonically static music; as a procedural tool, it affords a methodology based primarily on duration