This book is dedicated to three outstanding representatives of Slavic music of the 19th century - Frederic Chopin, Bedřich Smetana and Pyotr Ilyich Tchaikovsky, as well as Gustav Mahler, who equally belongs to the 20th century. The author tries to reconstruct the diseases and causes of death of these great composers, and also to clear them of speculation and legends, to establish indisputable diagnoses from the point of view of modern medicine.