Portrait Of John Derrington James Millar (1735-1805)

The picture has something of this: portrait, people, man, wear, music, facial hair, mustache, jacket, lid, leader, outfit, indoors, outerwear, neckwear, tie, light.
Perhaps it’s a close up of a painting of a man in a brown coat and white hair wearing a white hat and holding a piece of paper in his hand.