Quadrille, a dance of French origin for an even number of couples, usually four, forming a square. The word originally was applied to a group of horsemen, magnificently dressed, who performed riding maneuvers for entertainment.

The dance was introduced in the 18th century as a "contredanse" in the ballet. As a social dance it began early in the 19th century, during the Napoleonic period, and was taken to England in 1816. It remained popular until it was replaced by the polka in the 1840s.

The quadrille is divided into five parts, alternating between 6/8 and 2/4 time. Its music was usually based on popular and operatic airs.

--Encyclopedia Americana