On December 5, 1791, the composer Wolfgang Amadeus Mozart died at his home in Vienna at the age of 35. People have studied and guessed about the reasons for his death. The main topics of disagreement are: Different opinions about each of these topics have changed a lot over time.

The course of Mozart's final illness

The Mozart scholarship has long relied on the accounts of early biographers, who based their writings largely on the memories of Mozart’s wife, Constanze, and her sister, Sophie Weber. These memories were recorded in biographies by Franz Xaver Niemetschek and Georg Nikolaus von Nissen. For example, the biography by Hermann Abert mostly followed this account. Here is a summary of this view.

In August 1791, Mozart traveled to Prague to oversee the performance of his new opera, La clemenza di Tito (K. 621). At this time, he was already very ill. Niemetschek wrote that Mozart looked pale and sad, though he often showed good humor by joking with friends. After returning to Vienna in mid-September 1791, Mozart’s health gradually worsened. For a time, he continued working and completed his Clarinet Concerto (K. 622), made progress on his Requiem (K. 626), and conducted the premiere of The Magic Flute (K. 620) on 30 September. However, he became increasingly worried and upset about his health. Niemetschek recorded an account from Constanze:

After returning to Vienna, Mozart’s illness became more visible, and he grew very depressed. His wife was deeply troubled by this. One day, while driving in the Prater with him, Constanze tried to distract him. Sitting alone together, Mozart began talking about death and said he was writing the Requiem for himself. He cried and said, “I feel certain that I will not live much longer; I am sure I have been poisoned. I cannot get rid of this idea.”

Constanze tried to comfort her husband by encouraging him to pause work on the Requiem and instead finish the Kleine Freimaurer-Kantate (K. 623), a piece celebrating the opening of a new Masonic temple for Mozart’s lodge. This worked temporarily—the cantata was completed and successfully performed on 18 November. Mozart told Constanze he felt happy about the premiere. He reportedly said, “Yes, I see I was ill to have had such an absurd idea of having taken poison. Give me back the Requiem, and I will continue with it.”

However, Mozart’s worst symptoms returned, along with the belief that he had been poisoned. He became too sick to move and was bedridden on 20 November, suffering from swelling, pain, and vomiting.

From this point, scholars agree that Mozart was very ill. He died about two weeks later, at his home in Vienna, on 5 December at 12:55 a.m.

In recent years, the idea that Mozart was in a steady decline and despair during his final months has been questioned. Cliff Eisen oversaw the 2007 reissue of Abert’s biography, adding many footnotes. While generally agreeing with Abert, Eisen criticized the section about Mozart’s death, stating that Abert’s evidence was selective and focused on a specific story. Most of the testimony comes from people who did not know Mozart well and had personal or financial reasons to share certain views. Although these accounts are based on people who knew Mozart or saw him die, they may not be accurate. Eisen noted that Mozart was unwell in Prague but there is no proof he was “very ill” or that his health “continued to deteriorate.” Abert himself later wrote that Mozart’s health improved in October and early November.

In the Cambridge Mozart Encyclopedia, Eisen wrote about the decline-and-despair account:

Later sources describe Mozart as working hard on his Requiem while fearing his own death. However, these accounts are hard to match with the cheerful tone of his letters from most of November. Constanze’s earliest account, published in Niemetschek’s 1798 biography, said Mozart told her he wanted to try writing a Requiem, as church music had always interested him. There is no mention that the work was a burden to him.

As for why Constanze and Sophie might have had “complicated motives,” Halliwell suggested they were not objective because Constanze needed money. She earned income from benefit concerts and possibly a pension from the Emperor after Mozart’s death.

Christoph Wolff, in his 2012 book Mozart at the Gateway to his Fortune, disagreed with the idea that Mozart’s final years were a steady decline into despair. He also disagreed with interpretations that Mozart’s music from 1791 reflects late-life sadness, such as the “hauntingly beautiful autumnal world” of his compositions from that year.

Cause of death

Historian William Stafford explained the difficulty in determining what disease caused Mozart’s death:

There is very little direct evidence about Mozart’s final illness and death. Most information comes from later writers who described what others supposedly said. This information is limited and sometimes unclear or incorrect. Many later authors used these uncertain details to support their own theories without checking their accuracy.

In the parish record, it says Mozart died from "severe miliary fever." The term "miliary" refers to tiny bumps on the skin, but this was not the actual name of the disease.

Mozart had many health problems throughout his life, including smallpox, tonsillitis, bronchitis, pneumonia, typhoid fever, rheumatism, and gum disease. However, it is unclear if these conditions contributed to his death.

Many theories exist about what caused Mozart’s death.

One idea, first suggested in 1824 by Dr. Eduard Guldener von Lobes, a contemporary of Mozart, proposed that an infectious disease spreading in Vienna in 1791 caused Mozart’s death. Guldener, who had worked in public health in Vienna, wrote to a journalist named Giuseppe Carpani, describing Mozart’s illness. He stated that a widespread fever affected many people in Vienna at the time and that Mozart’s doctors had predicted the illness’s outcome accurately. Guldener also claimed the idea that Antonio Salieri poisoned Mozart was false. His letter was included in Carpani’s published report.

Later, in 2009, researchers Zegers, Weigl, and Steptoe studied deaths in Vienna around the time of Mozart’s death. They found that deaths from edema (a key symptom of Mozart’s illness) were higher among young men during that period. They suggested Mozart may have died from a streptococcal infection that led to kidney failure, a condition called poststreptococcal glomerulonephritis. This disease was known as "Wassersucht" in 18th-century Austria.

Other experts, such as Jenkins (2006) and Davies (1983), also supported the idea that an epidemic disease caused Mozart’s death. Davies suggested Mozart may have caught the illness at the premiere of his final work, the Little Masonic Cantata, which he conducted.

Some people believe Mozart’s doctor, Dr. Closset, may have worsened his condition. A relative of Mozart, Sophie Weber, claimed Closset delayed treating Mozart and used cold compresses that may have worsened his illness.

A 1994 study in Neurology proposed Mozart died from a blood clot on the brain, called a subdural hematoma. This theory was based on a skull believed to be Mozart’s, which showed signs of a head injury and a possible chronic blood clot. A 2000 study by Fitzgerald, Mackowiak, and Zaslaw suggested rheumatic fever as a possible cause.

Other theories include trichinosis (a disease from undercooked meat), hypochondriasis (excessive worry about health), and the use of antimony in patent medicines. A 2011 study suggested vitamin D deficiency may have contributed to Mozart’s health issues.

An early rumor claimed Antonio Salieri poisoned Mozart, but this was proven false because Mozart’s symptoms did not match poisoning. Salieri denied the accusation but was affected by public belief in it.

Some unusual theories blame the Masons, Jews, or both for Mozart’s death. These ideas are described as outlandish by historian William Stafford.

Funeral

Baron Gottfried van Swieten, a friend and supporter of Mozart, arranged his funeral. According to the Grove Dictionary of Music and Musicians, Mozart was buried in a common grave, following Viennese customs of the time. This burial took place at the St. Marx Cemetery outside Vienna on December 7. Otto Jahn wrote in 1856 that Salieri, Süssmayr, van Swieten, and two other musicians were present at the funeral.

The belief that Mozart was buried in a pauper's grave is incorrect. A "common grave" referred to a burial for someone who was not part of the aristocracy. It was an individual grave, not a shared one. However, after ten years, the city had the right to reuse the grave for another burial. Graves of aristocrats were not treated this way.

Another reason for Mozart’s simple burial was his dislike of elaborate funeral rituals, which he considered "superstitious."

A description of Mozart’s funeral, attributed to Joseph Deiner, appeared in the Vienna Morgen-Post on January 28, 1856. It stated that the night of Mozart’s death was dark and stormy, and the funeral also faced heavy rain and snow. Only a few friends and three women accompanied the body. Mozart’s wife was not present. As the storm worsened, the group decided to return to the "Silver Snake," a local tavern. Deiner, the owner, was also at the funeral.

Slonimsky noted that this story became widely accepted in Mozart biographies. However, Deiner’s account of the weather does not match records from December 6. Diarist Karl Zinzendorf wrote that the day had "mild weather and frequent mist." The Vienna Observatory recorded temperatures between 37.9 and 38.8 degrees Fahrenheit (2.8°C–3.8°C) and a "weak east wind" all day.

Aftermath

After Mozart's death, Constanze worked to ensure her family had money. The Mozarts had two young children, and Mozart had left unpaid debts. She asked the Emperor for help on December 11, 1791, to receive a pension because Mozart had served the Emperor as a part-time composer. She also organized concerts featuring Mozart's music and helped publish many of his works. Over time, this allowed Constanze to become financially stable.

Soon after Mozart's death, a biography about him was started by Friedrich Schlichtegroll. He used information from Mozart's sister, Nannerl. Franz Niemetschek wrote another biography with Constanze's help. Later, Constanze helped her second husband, Georg Nikolaus von Nissen, write a more detailed biography, which was published in 1826. For more information, see Biographies of Mozart.

Mozart's musical reputation grew after his death. A 20th-century biographer, Maynard Solomon, described a strong increase in interest in Mozart's work after he died. Many publishers released editions of his compositions.

In 1801, what may have been Mozart's skull was exhumed. Scientists examined it between 1989 and 1991 to confirm its identity.

Remembrances of Mozart's death

People who were present when Mozart died later wrote down their memories, either on their own or through interviews. The stories they shared often disagree, which may be because some events were not recorded until the 1820s, when the witnesses' memories might have become less clear.

Benedikt Schack, a close friend of Mozart who had a role in The Magic Flute, told an interviewer that on Mozart’s final day, he took part in a rehearsal of the Requiem. Schack’s account was published in an obituary in the Allgemeine musikalische Zeitung on July 25, 1827:

On the day before his death, Mozart had the Requiem score brought to his bed. At 2:00 p.m., he sang the alto part. Schack, a family friend, sang the soprano line, as he had done before. Mozart’s brother-in-law, Hofer, sang the tenor part, and Gerl, a later bass singer at the Mannheim Theater, sang the bass part. They were singing the first part of the Lacrimosa when Mozart began to cry, set the score aside, and died 11 hours later at 1:00 a.m. on December 5, 1791.

Biographer Niemetschek shared a similar but less detailed story: On the day of his death, Mozart asked for the Requiem score to be brought to his bedside. He said, “Did I not say before that I was writing this Requiem for myself?” Then, he looked through the work again with tears in his eyes.

The common belief that Mozart dictated parts of the Requiem to his student Süssmayr on his deathbed is not supported by Solomon, who notes the first mention of this claim was in 1856. However, Süssmayr’s handwriting appears in the original Requiem manuscript, and Sophie Weber claimed she remembered Mozart giving instructions to Süssmayr.

A letter from composer Ignaz von Seyfried, dated 1840, states that on his last night, Mozart was thinking about the opera The Magic Flute, which was being performed. Mozart is said to have whispered to Constanze about her sister Josepha Hofer, the soprano who first performed the role of the Queen of the Night: “Quiet, quiet! Hofer is just taking her top F; now my sister-in-law is singing her second aria, ‘Der Hölle Rache’; how strongly she strikes and holds the B-flat: ‘Hört! hört! hört! der Mutter Schwur’ [Hear! hear! hear! the mother’s oath].”

Solomon noted that Mozart’s biographers often avoided discussing the more difficult details of his death. He wrote that Constanze told Nissen that just before dying, Mozart asked her what his doctor, Dr. Closset, had said. When she lied to comfort him, he said, “It isn’t true,” and became very upset: “I shall die now, when I am able to take care of you and the children. Ah, now I will leave you unprovided for.” As he spoke these words, he vomited, and it came out in a stream—it was brown, and he died.

Mozart’s older son, Karl, who was seven years old at the time, later wrote that a few days before his father’s death, Mozart’s body became so swollen that he could not move. There was also a strong smell, which showed an internal breakdown that worsened after death, making an autopsy impossible.