Since the beginning of the twentieth century, the cross-pollenization of world musical materials and practices has accelerated precipitously, due in large part to advances in higher-speed communications and travel. We live now in a world of global musical practice that will only continue to blossom and develop through the twenty-first century and beyond. Yet music theory as an academic discipline is only just beginning to respond to such a milieu. Conferences, workshops and curricula are for the first time beginning to develop around the theme of 'world music theory', as students, teachers and researchers recognize the need for analytical concepts and methods applicable to a wider range of human musics, not least the hybrid musics that influence (and increasingly define) more and more of the world's musical practices. Towards a Global Music Theory proposes a number of such concepts and methods stemming from durational and acoustic relationships between 'twos' and 'threes' as manifested in various interrelated aspects of music, including rhythm, melody, harmony, process, texture, timbre and tuning, and offers suggestions for how such concepts and methods might be applied effectively to the understanding of music in a variety of contexts. While some of the bases for this foray into possible methods for a twenty-first century music theory lie along well established acoustical and psycho-acoustical lines, Dr Mark Hijleh presents a broad attempt to apply them conceptually and comprehensively to a variety of musics in a relevant way that can be readily apprehended and applied by students, scholars and teachers.