|How to conduct Mahler? Ranging from Abbado to Muti, Rattle, Haitink and Chailly, five conductors share their secrets. In 1920, the first Mahler festival was held to celebrate Willem Mengelberg's twenty years at the head of the Concertgebouw Orchestra. For sixteen days, Amsterdam echoed to the sounds of the symphonies and vocal pieces of the Viennese composer, whose entire works were played by the Concertgebouw. Seventy-five years later, another Mahler festival was held, this time with the three orchestras the composer conducted in his own time. the philharmonic orchestras of Berlin and Vienna and the Concertgebouw. Claudio Abbado, Riccardo Muti, Riccardo Chailly, Simon Rattle and Bernard Haitink, the conductors who took part in this adventure, share their love for Mahler in front of Franck Scheffer's camera. We see them work relentlessly with their orchestras and talk freely of the very strong ties they have maintained with Mahler's music, most of them since childhood. These lessons in orchestra conducting with the greatest conductors one could ever imagine gathered together in a single film are also lessons in music that shed a wonderful light on the complexity of Mahler's music.