For example Mr. and Mrs. Peachum chastise their daughter when she believes that she wants to get married. The terrible treatment of Polly is a common theme throughout the entire play. Constantly she is called a slut or a whore by her mother. The name calling by a parent is the first idea of high people and low people within in the familial ties. By calling her something degrading and something that is definitely below high class people, Mrs. Peachum automatically sets herself up as the high people. She is not an adorer of her daughter or one with constructive criticism, she only brings her daughter down and mentally makes Polly lower her idea of her own social status.
Through this Gay himself through his writing has reached out and personified the dividing factor between the opera and the beggars. The parents are the opera, they are the high people in everyone's eyes while Polly is the low person, the thief. She has gone out to find love and through this adventure she has found Macheath. In a sense she is a thief of love because she went behind other's wishes.
Gay's integration of the high people and the low people other than the initial in the title, "the BEGGAR'S OPERA" is interesting to watch and see progress throughout the writing. You can see each party shift and change throughout the writing and of course how each regard each other, Mr. and Mrs. Peachum to Polly and Polly to Mr. and Mrs. Peachum. Again also the bookends of the Player and the Beggar at the beginning and at the end of the play is of course also marking this idea of high and low people.