Franz Xaver Wolfgang Mozart (26 July 1791 – 29 July 1844), also known as Wolfgang Amadeus Mozart, Jr., was the youngest child of six born to Wolfgang Amadeus Mozart and his wife Constanze. He was the younger of his parents' two surviving children.[1] He was a composer, pianist, conductor, and teacher whose musical style was an early Romanticism, heavily influenced by his father's mature style.

Franz Xaver Wolfgang Mozart was born in Vienna, five months before his father's death. Although he was baptized Franz Xaver Mozart, from birth on he was always called Wolfgang by his parents.[2] He received excellent musical instruction from Antonio Salieri and Johann Nepomuk Hummel, and studied composition with Johann Georg Albrechtsberger and Sigismund von Neukomm.[3] He learned to play both the piano and violin. Like his father, he started to compose at an early age. "In April 1805, the thirteen-year-old Wolfgang Mozart made his debut in Vienna in a concert in the Theater an der Wien."[4]

Wolfgang became a professional musician and enjoyed moderate success both as a teacher and a performer. Unlike his father, he was introverted and given to self-deprecation. He constantly underrated his talent and feared that whatever he produced would be compared with what his father had done.

Needing money, in 1808, he travelled to Lemberg, where he gave music lessons to the daughters of the Polish count Wiktor Baworowski. Although the pay was good, Franz felt lonely in the town of Pidkamin, near Rohatyn, so in 1809, he accepted an offer from the imperial chamberlain, Count von Janiszewski, to teach his daughters music in the town of Burshtyn. Besides teaching, he gave local concerts, playing his own and his father's pieces. These concerts introduced him to the important people in Galicia.

After two years in Burshtyn, he moved to Lemberg where he spent more than 20 years teaching (with students including Julie von Webenau, née Baroni-Cavalcabò) and giving concerts. Between 1826 and 1829, he conducted the choir of Saint Cecilia, which consisted of 400 amateur singers. In 1826, he conducted his father's Requiem during a concert at the Greek Catholic cathedral of St. George. From this choir, he created the musical brotherhood of Saint Cecilia, and thus the first school of music in Lemberg. He did not give up performing and in the years 1819 to 1821 traveled throughout Europe. In 1819 he gave concerts in Warsaw, Elbing and Danzig (Gdańsk).

In the 1820s, Franz Xaver Wolfgang Mozart was one of 50 composers to write a variation on a theme of Anton Diabelli for part II of the Vaterländischer Künstlerverein. Part I was devoted to the 33 variations supplied by Beethoven, which have gained an independent identity as his Diabelli Variations, Op. 120.

In 1838, he left for Vienna, and then for Salzburg, where he was appointed as the Kapellmeister of the Mozarteum. From 1841, he taught the pianist Ernst Pauer. He died from stomach cancer on 29 July 1844 in the town of Karlsbad, where he was buried.

He never married, nor did he have any children. His will was executed by Josephine de Baroni-Cavalcabò, the dedicatee of his cello sonata[3] and a longtime patroness. The shadow of his father loomed large over him even in death. The following epitaph was etched on his tombstone: "May the name of his father be his epitaph, as his veneration for him was the essence of his life."