The advent of the waltz marked an enormous change in the way men and women danced in polite society. Prior to the waltz, all European social dances were communal sequence dances -- communal because all the dancers on the floor took part in a pre-set pattern. With the waltz, couples were independent of other couples, and were turned towards one other. As the waltz evolved, the contact between the man and the woman became close (which was considered scandalous in some quarters). The Congress of Vienna in the early 19th century, together with the famous compositions by Josef Lanner, Johann Strauss I and his son, Johann Strauss II, helped popularize the waltz around the world.