Sound is an inherently spatial phenomenon. No matter what its point of origin, be it a musical instrument, a voice, an audio speaker, or another sound-producing entity, sound must navigate space before reaching our ears. On this journey it enters into a complex relational dynamic with the surrounding environment: it may be amplified, distorted, reverberated, dissipated and subject to a multitude of transformations which modify it in different ways. While this dynamic is an intrinsic part of any sonic event, certain artistic endeavours have sought to exploit this spatial aspect of sound as a distinct parameter in its own right. Though spatial experiments have a long history in western music stretching back centuries, the search for novel means of expression in the twentieth century led to an unprecedented investigation into the spatiality of sound as an integral component of the work. From Edgard Varèse’s Poème électronique to Karlheinz Stockhausen’s Helicopter String Quartet, such concerns have been at the centre of some of the canonic works of musical modernism. In the discipline of sound art, auditory dialogues with the surrounding space have been the defining feature of sound installations by Max Neuhaus, Bernhard Leitner, Maryanne Amacher and others, who have sought to locate sound in relation to architecture. While such work grew out of developments in the wider field of art installation, increasingly the practices of both sound and art installation have converged in the work of artists such as Janet Cardiff and Zimoun forming multi-sensory experiences. Expanding outwards, the multi-site sound installations of Bill Fontana have developed the notion of spatiality across geographical locations while recent innovations in communication and digital technologies have created virtual networks, redefining our conception of space and presenting new possibilities for music, sound art and visual art.