Carl Reinecke's 'Undine' was published in 1882 as a sonata for flute and piano and to this day is one of his most frequently played works. In 1885 Reinecke also published a version for clarinet and piano in which the piano part remained unchanged whereas the flute part was adjusted to the technical and tonal qualities of the clarinet. Thus, Reinecke was able to add a striking work to the small clarinet-piano repertoire. The current edition is based on the version for flute and piano, published in the Wiener Urtext Edition series, which, is based on the German and English first edition, exchanging the flute part for the clarinet arrangement published in 1885. Notes on interpretation specially written for the clarinet version take into account both historically adequate playing techniques and questions regarding the musical text, extra-musical programme and performance practice. A reliable musical text, optimised page turns and a comfortable overview are essential features of the current edition with regard to form and layout.