The Sonata for solo violin is not only a piece unique in its genre, presenting extreme challenges of instrumental technique, written for a virtuoso performer, but also one of the deepest and most abstract works of the composer, whilst the 44 duos of 13 years earlier, consisting of a series of wonderful miniatures, arrangements of folk melodies, lead the violin pupil all the way from his first unsteady steps in music, to a brief concert piece still within the framework of a small form.