Carl Czerny (1791-1857) was an Austrian composer, teacher, and pianist of Czech origin whose music spanned the late Classical and early Romantic eras. His vast musical production amounted to over a thousand works and his books of studies for the piano are still widely used in piano teaching. He was one of Ludwig van Beethoven's best-known pupils. At the age of fifteen, Czerny began a very successful teaching career. Basing his method on the teaching of Beethoven and Muzio Clementi, Czerny taught up to twelve lessons a day in the homes of Viennese nobility. His 'star' pupils included Theodor Döhler, Stephen Heller, Sigismond Thalberg, and Ninette de Belleville. In 1819, the father of Franz Liszt brought his son to Czerny. The better known part of Czerny's repertoire is the large number of didactic piano pieces he wrote. Czerny's body of works also include arrangements of many popular opera themes. The majority of the pieces called by Czerny "serious music" (masses, choral music, quartets, orchestral and chamber music) remain in unpublished manuscript form and are held by Vienna's Society for the Friends of Music, to which Czerny willed his estate.