Mozart never took an IQ test. The ≈155 is Catharine Cox's 1926 estimate — comparatively modest, because her method under-weighted musical genius despite his extraordinary documented precocity.
The most precocious child in Cox's sample, scored like a lawyer
Cox's raters scored childhood milestones mostly in reading, languages, logic and academic work. A five-year-old writing minuets didn't map neatly onto that scale. His figure is one of the clearest arguments that the method measured a particular kind of achievement, not ability in general.
A child performer in every court in Europe
His father Leopold, a court musician in Salzburg, taught him and his sister Nannerl, then took them on the road: Munich and Vienna at six, then a three-year tour through Paris and London, playing for kings and the public.
In Rome at fourteen he is said to have written out Allegri's closely guarded Miserere from memory after hearing it in the Sistine Chapel.
Education: no school, every teacher in Europe
He never attended a school. His father taught him everything from arithmetic to counterpoint, and the tours put him in front of the best musicians of the age.
Keyboard at three or four, then violin and composition. Leopold wrote down his first minuets in his sister Nannerl's music notebook.
Arithmetic, reading, Latin, Italian and French — taught at home and on the road.
J. S. Bach's youngest son befriended the eight-year-old and shaped the style of his first symphonies.
Studied counterpoint with Europe's most respected teacher.
Passed its admission exam at 14, well below the usual minimum age of 20.
Knighted by Pope Clement XIV at 14.
Weekly sessions studying manuscripts of J. S. Bach and Handel transformed his counterpoint.
The nine most famous notes he wrote
A serenade for strings he never saw published. Press play, or tap the keys yourself.
Vienna, 1781–1791: ten years, five masterpieces a year
He broke with his Salzburg employer in 1781 and lived as a freelancer in Vienna — performer, teacher and composer, often in debt. He died in December 1791 with the Requiem unfinished; it was completed by his pupil Süssmayr.
The Köchel catalogue, by genre
Ludwig von Köchel listed 626 works in 1862, ending with the Requiem, K. 626. Pick a genre for the landmarks beyond the Vienna masterpieces above.
The “little G minor”, written at 17.
Written to impress Parisian audiences.
Adapted from a serenade for a Salzburg family.
Written in about four days.
Timeline
Reading the ≈155
A Cox-era estimate that says more about the method's blind spot for music than about Mozart. A retrospective inference, not a measurement.
Sources
- Cox, C. M. (1926). The Early Mental Traits of Three Hundred Geniuses
- Köchel, L. von (1862). Chronologisch-thematisches Verzeichnis
- Solomon, M. (1995). Mozart: A Life. HarperCollins
- Mozart family correspondence