The string quartets by Viennese composer Alexander Zemlinsky number among the most important contributions to the genre in the first half of the twentieth century. The Third String Quartet op. 19, composed in 1924, shows the mature master at the height of his creativity. The difference to the highly expressionistic Second String Quartet, written ten years earlier, could hardly be greater. With its four-movement form, an often linear style of writing and the ironic detachment of its tone, Zemlinsky’s op. 19 takes up the then current neoclassical tendencies of the 1920s. For this Henle Urtext edition, it was possible to consult the autograph score, the engraver’s copy proofread by the composer and the first edition, so that the edition is based on an optimal source foundation. The editorial work was generously supported by the Alexander Zemlinsky Fund, Vienna.