Published on the occasion of Lars Fredrikson's retrospective exhibition at the Musée d'Art Moderne et d'Art Contemporain in Nice, organized in collaboration with the Nouveau Musée National de Monaco and the artist's son, this book is the first monograph dedicated to the radical Swedish painter, draftsman, sculptor, and precursor of sound art (1926-1997). Over his long career the artist produced a vast and multidisciplinary corpus of works that aimed to question our perception - the borders between the visible and the invisible, presence and absence, inside and outside. The publication plays on the multiple rebounds and echoes in Fredrikson's works, in particular his nonlinear approach to art, his bodily exploration of vibrations, and his constant aim to grasp the invisible waves and frequencies that surround us - to render palpable the unseen that is actually right before our eyes.