The young man seated on the left is playing a theorbo; in front of him on the floor is its case. In the centre of the wall behind the figures is a landscape with a carved gilt frame and, on the left, a wall-sconce.
This painting is a copy of a composition by Caspar Netscher, the original (or best version) of which is signed and dated 1665 (Munich, Alte Pinakothek). There are a number of other replicas or copies of this design.