In seminar discussions and lectures held between 2013 and 2018, Ludger Brümmer and Hans Tutschku provide insights into their compositional work. Distinct musical ideas, methodological approaches, fundamental techniques, and aesthetic principles are clearly illustrated through selected analytical figures.

Additionally, the book documents the festival Das befreite Hören (January 15–19, 2018), which paid tribute, among others, to the pioneer of Musique Concrète Pierre Henry, who passed away in 2017. Furthermore, François Bayle, whose Adventures in Listening was the focus of the previous Signale volume (No. 23) with the participation of Brümmer and Tutschku, appears as a surprise guest.

Thus, this ninth edition of the cycle Composition and Musicology in Dialogue concludes, a quarter of a century after the publication of the first volume, the entire Signale aus Köln series. It offers both a historical perspective on music and a forward-looking vision of contemporary electroacoustic music.