At the origin of the project that constitutes "According to the custom of the waves" there was, however, no reflection, no reasoning of a conceptual type, but rather something more vague and inexplicable: a tremor, a hunch. Memory is not always constructed as a story, or as a recollection; it can often manifest itself under the kind of unconnected sensations of something that surprises us like an echo of already forgotten melodies. Music, whose presence has always accompanied, in one way or another, the work of the authors of this book, appeared one day, suddenly, as a symptom of a different experience, difficult to express, and launched this dialogue between image and word that is the result of a joyful exchange between two of the most significant voices of contemporary Spanish poetry.