The book describes how 20th-century music gave rise to different genres and subcultures, with each group developing its style. It discusses the separation and connection between music and society, as well as the impact of history on music. The author explores how classical music and neighboring genres intersect, with examples such as Duke Ellington and the Beatles. "The Rest is Noise" is aimed at connoisseurs and newcomers to classical music and offers diverse perspectives on the history of music in the 20th century.