University of Chicago Press, ISBN-13: 978-0226543178, English, 272 pages, 2018, USA

The invisibility of sound has led to various different interpretations of its structure and consequent impact on human beings. But its continuity over time and space and the inclusion of ‘silence’ in it, has led to various notions of sound as a permanent ‘flux’, only variating in components and intensity. In this book, Cox (also co-editor of the Audio Culture anthology) constructs and formalises the concept of “sonic flux”, conceived in an early form by Schopenhauer, Nietzsche and Deleuze, and furthered by Manuel DeLanda’s “A Thousand Years of Nonlinear History”. He considers a (non) linear history of music recording going back to recording audio ‘fluxes’, to the pivotal moment of the first phonograph enabling memory (“ghosts”) to contribute and intervene in fluxes; and then the electronic and digital infrastructure, infinitely intertwining with them. The author expands on his large knowledge of related artists and artworks, through a “patterned-matter energy” materialism, always returning to the flux as the primary component. The circulation of sound, transformed from noise, is then analysed through Marclay, Lucier, Kirkegaard, Lopez, Radigue, Lockwood and their “intensive continuum”, finally posing an urgent synaesthetic question: how can the relationship about sound and image be disjunctive?