Doubtless never has a work left behind such deep confusion, heightened by nearly three centuries of legends. The circumstances of the composition of the Requiem are not lacking in romantic mysteries: in July 1791, Mozart, exhausted by work and both moral and financial concerns, put the finishing touches to The Magic Flutewhen he receives a visit from a secret messenger. We know today that it was the steward of Count Walsegg, who, a widower and music lover, intended to obtain a mass for the dead in memory of his wife. We also know that the musician's death interrupted the work begun in the autumn of 1791. His wife Constance first entrusted the score to Eybler, who was unable to complete the work in turn, then to Süssmayer, the pupil to whom Mozart had given many indications for his Requiem . Recent work has attempted to disentangle the contributions of Mozart and his pupil, in order to establish an edition considered to be closest to the intentions of the musician.