Preparations for the Ball (4:00): Preparations for the Russell ball are underway, and music plays an important part.
Bertha Russell: “We’ll take out the piano and build the podium for the band in this alcove.”
Practicing the Quadrille (11:13): In this scene, we see Gladys Russell, Carrie Astor, and friends practicing the quadrille, a popular Gilded Age dance. The tradition of having live piano accompaniment for dance classes still exists and I’ve had friends who made good money when they were starting off their career doing this. One of the funniest lines in this scene:
Dance Instructor: “Remember, everyone. The quadrille is not a romping dance.”
The music is a piano version of Festival-Quadrille on English Themes, No. 6 Finale, Op. 341 by Johann Strauss II (1825-1899), which was originally premiered in 1867 at Covent Garden in London. Strauss was a very popular Austrian composer of light music, particularly dance music and operettas. He was known as “The Waltz King” and is most famous for works like “The Blue Danube.” In the 1870s, Strauss and his orchestra toured the United States, where he took part in the World’s Peace Jubilee and International Musical Festival in Boston at the invitation of bandmaster Patrick Gilmore. As was customary at the time, requests for personal mementos from celebrities were often in the form of a lock of hair. In the case of Strauss during his visit to America, his valet obliged by clipping Strauss' black Newfoundland dog and providing "authentic Strauss hair" to adoring female fans. 
Johann Strauss II.