Oliver Sacks examines the relationship with music of patients, ordinary people or professional musicians to shed unusual light on this phenomenon. Through anomalies such as "amusia" or the inability to feel music, the hypermusical Williams syndrome, a strange phenomenon of extreme sociability, musical hallucinations or music inspiring authentic terror, Sacks develops a lucid analysis of how music is a key factor in creating human identity, whether in a pathogenic way or as a positive agent in treating Parkinson's, dementia, Tourette syndrome, encephalitis or temporal lobe attacks. Sacks once again reveals himself as a splendid narrator, with the humor, erudition and the vast scientific and humanistic culture to which he has accustomed us. "More interested in human experience than in psychological theory, Sacks is closer to Herman Melville than to Charles Darwin" (The Sunday Times).