The "Stadtklang" project by Julien Herion and Sebastian Siepe is an experimental composition: a collage of city soundscapes, the thoughts of its residents and music that was completely coded in programming language "Csound". This book accompanies the whole experience in realtime: while listening, you can follow the corresponding code in the very moment it is converted into music. The book is—as the composition—divided by five chapters, marked as orange pages. By turning the semitransparent pages in between them, you gradually process from one chapter to the next.