For 10 points, Mr. and Mrs. Andrews is a portrait by, what artist of the portrait of Jonathan Buttall, The Blue Boy?
In one work, this artist contrasted a sitter's silver dress with the red curtain behind her as she, leaning to the left and crossing her legs above the knee, rests a guitar in her lap, which stands as a reference to her scandalous concerts.  A girl with a torn right sleeve stares listlessly to the right while holding a puppy in her right arm and a large brown ceramic jug in her left in another work by this artist. This artist of a portrait of Ann Ford and Cottage Girl with a Dog and a Pitcher utilized the figures in Rubens's Descent from the Cross as the models for a group of peasants one of whom, a woman, is being helped to climb into the title object, while two others fight over a drink. In addition to that work, The Harvest Wagon, this artist left a spot on the lap of one sitter unfinished in a portrait that sees a dog look up attentively at his master, who is resting his musket in the crook of his arm. For 10 points, Mr. and Mrs. Andrews is a portrait by, what artist of the portrait of Jonathan Buttall, The Blue Boy?
In one work, this artist contrasted a sitter's silver dress with the red curtain behind her as she, leaning to the left and crossing her legs above the knee, rests a guitar in her lap, which stands as a reference to her scandalous concerts.  
Thomas Gainsborough 