Wolfgang Amadeus Mozart (baptised Johannes Chrysostomus Wolfgangus Theophilus Mozart) was an influential composer of the Classical era, who showed prodigious ability from his earliest childhood. Competent on keyboard and violin, he composed from the age of five and performed before European royalty. At 17, he was engaged as a court musician in Salzburg, though he later moved to Vienna, where he achieved fame but little financial security. During his final years in Vienna, he composed many of his best-known symphonies, concertos, and operas, and portions of the Requiem, which was largely unfinished at the time of his death. The circumstances of his early death have been much mythologized. He composed over 600 works, many acknowledged as pinnacles of symphonic, concertante, chamber, operatic, and choral music. He is among the most enduringly popular composers, and his influence on subsequent Western music is profound; Beethoven composed his own early works in the shadow of Mozart, and Haydn wrote that "posterity will not see such a talent again in 100 years."