Colorado Symphony Blog

The Requiem took on an increasingly personal significance, and he pressed himself to continue working despite his illness.

The story has inspired generations of listeners, but separating historical fact from later legend is important. We cannot know precisely what Mozart believed or how much the commission shaped his final days. What we do know is that he died in Vienna on December 5, 1791, at just 35 years old, leaving the Requiem unfinished.

The truth behind the commission was strange enough without the mythology. The patron was Count Franz von Walsegg, an amateur musician known for commissioning works anonymously and presenting them as his own. He wanted the Requiem to commemorate his wife, Anna, who had died earlier that year. The mysterious messenger was the count’s valet.

Mozart never learned the identity of the person who had commissioned the work.

The music Mozart left behind

Mozart completed the opening Introit and Kyrie and left substantial material for several subsequent sections. But the score was far from finished when he died.

His widow, Constanze, turned to Joseph Eybler, a composer and friend of Mozart, to help complete it. When Eybler stopped, Mozart’s pupil Franz Xaver Süssmayr took over, using Mozart’s surviving sketches and instructions to finish the work and supply music for its concluding movements.

The version audiences most commonly hear today is Süssmayr’s completion. That means the Requiem we know is a collaboration across an extraordinary divide: Mozart’s final musical ideas, preserved and developed by the people who knew his work, and the efforts of a student determined to bring his teacher’s last composition to the world.

The circumstances of its completion have prompted generations of scholars and musicians to debate which passages are Mozart’s, which belong to Süssmayr, and how closely the finished score reflects the composer’s intentions. Yet the work’s impact has never depended on resolving every question about its authorship.

What matters is the music itself.

A masterpiece that outlived its creator

The Requiem was first performed in its completed form in December 1793, at a service arranged by Count Walsegg in memory of his wife. The count initially claimed the composition as his own, but Constanze later helped establish Mozart’s authorship as she worked to publish her late husband’s music. The score appeared in print in 1802.

By then, the work had begun its journey into the musical imagination. Its mysterious origins, unfinished manuscript, and association with Mozart’s death helped fuel its legend, particularly during the Romantic era.