A private concert is taking place in the Neapolitan apartment of the expatriate, Lord Fortrose. He stands, with his back to us, in the centre of the scene. His friend, Sir William Hamilton, is on his left, and the violinist, Gaetano Pugnani, is on his right. In the left-hand corner, the artist has painted himself, working on this picture. The two keyboard players have been identified as the fourteen-year old Wolfgang Amadeus Mozart and his father, Leopold, who visited Naples in the summer of 1770.