Shostakovich's music is often described as being dynamic, energetic. But what is meant by 'energy' in music? After setting out a broad conceptual framework for approaching this question, Michael Rofe proposes various potential sources of the perceived energy in Shostakovich's symphonies, describing also the historical significance of energeticist thought in Soviet Russia during the composer's formative years. The book is in two parts. In Part I, examples are drawn from across the symphonies in order to demonstrate energy streams within various musical dimensions. Three broad approaches are adopted: first, the theories of Boleslav Yavorsky are used to consider melodic-harmonic motion; second, Boris Asafiev's work, with its echoes of Ernst Kurth, is used to describe form as a dynamic process; and third, proportional analysis reveals numerous symmetries and golden sections within local and large-scale temporal structures. In Part II, the multi-dimensionality of musical energy is considered through case studies of individual movements from the symphonies. This in turn gives rise to broader contextualised perspectives on Shostakovich's work. The book ends with a detailed examination of why a piece of music might contain golden sections.