Synaesthesia is a remarkable phenomenon: It unites scientists and artists, as well as different disciplines such as neuroscience, psychology, music, art, philosophy and linguistics. This book is a collection of interviews with scientists and artists who explore synaesthesia. We asked similar questions to each of them: e.g., How can synaesthesia be defined? Is it inborn? Are synaesthetes special? How does it influence visual artists? Thirty people talked with us, including many of the world’s leading synaesthesia researchers, such as Richard E. Cytowic, Lawrence E. Marks, Jamie Ward and Edward M. Hubbard, and famous synaesthete artists such as Anne Patterson, Carol Steen, Timothy B. Layden and Raewyn Turner. Our interview partners from North and South America, Europe, Australia and New Zealand helped create this unique collection and provided many insightful ideas, colourful illustrations and unforgettable descriptions of their experiences.