Wolfgang Amadeus Mozart works in the shadow of Mozart, and Joseph Haydn wrote: "posterity will not see such a talent again in 100 years". Wolfgang Amadeus Mozart was born on 27January 1756 to Leopold Mozart (1719–1787) and Anna Maria, née Pertl (1720–1778), at 9 Getreidegasse in Salzburg. This was the capital of the Archbishopric of Salzburg, an ecclesiastic principality in what is now Austria, then part of the Holy Roman Empire. He was the youngest of seven children, five of whom died in infancy. His elder sister was Maria Anna Mozart (1751–1829), nicknamed "Nannerl". Mozart was baptized the day after his birth, at
Wolfgang Amadeus Mozart Theme from Mozart's Opera "Die Zauberflöte" (1822), Frédéric Chopin's Variations on "Là ci darem la mano" from "Don Giovanni" (1827), and Max Reger's Variations and Fugue on a Theme by Mozart (1914), based on the variation theme in the piano sonata K. 331; Pyotr Ilyich Tchaikovsky wrote his Orchestral Suite No. 4 in G, "Mozartiana" (1887), as a tribute to Mozart. For unambiguous identification of works by Mozart, a "Köchel catalogue number" is used. This is a unique number assigned, in regular chronological order, to every one of his known works. A work is referenced by the abbreviation "K." or