Introduction

This PressBook introduces and develops a number of concepts necessary for understanding twentieth- and twenty-first century music. The objective is to provide a free, accessible, concise resource that addresses certain gaps and biases in current textbook offerings and Wikipedia. All of the topics feature examples across popular and classical styles with links to YouTube. There is an attempt to document variance in terminology amongst musicians. There is a considerable simplification and a de-emphasis of set theory and serialism, which have constituted the core of many twentieth-century theory textbooks. I hope you find it rewarding.