Requiem by Mozart is possibly the most popular composition in the history of music among music lovers. A series of circumstances, between history and fiction, made it a universal classic work almost from its creation. For the first time in the bibliography in Spanish, the book The «Requiem» by Mozart. A cultural history describes the intense presence it had in 19th century Spain, in dozens of cities with different urban profiles (among others, the singular cases of Olot, Cervera and Barcelona). The writer and philosopher Rafael Argullol and Miguel Ángel Marín, author of the book, will talk to reveal some keys to this monumental work: from the aesthetic context and the mythical dimension of the Requiem to the challenge of listening to a mass of the dead from an operatic perspective.