Originally a duo for two celli, whose first part has been slightly altered for the interplay with double bass, while the second part is tailor-made for the double bass. The two parts alternate with the themes. These are written in a diatonic nature so that they can be easily played by the double-bass in its original tuning. Special attention should be paid to the second movement: in the middle section the double bass may show its virtuosity in a major Cantilena. This Cantilena has so much romantic and emotional passion that it seems to have been composed especially for the double bass.