Washington, D.C., formally the District of Columbia and commonly referred to as Washington or D.C., is the capital of the United States of America.

Founded after the American Revolution as the seat of government of the newly independent country, Washington was named after George Washington, first President of the United States and Founding Father.

Washington is the principal city of the Washington metropolitan area, which has a population of 6,131,977.

Washington has been described as an important political capital, owing to its status as the seat of the United States federal government.

Washington is one of the most visited cities in the world, with more than 20 million annual tourists.

A choir (also known as a quire, chorale or chorus) is a musical ensemble of singers.

Choral music, in turn, is the music written specifically for such an ensemble to perform.

Choirs may perform music from the classical music repertoire, which spans from the Medieval era to the present, or popular music repertoire.

Most choirs are led by a conductor, who leads the performances with arm and face gestures.

Maryland is a state in the Mid-Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east.

The state's largest city is Baltimore, and its capital is Annapolis.

Among its occasional nicknames are Old Line State, the Free State, and the Chesapeake Bay State.

The state is named after the English queen Henrietta Maria of France.

An orchestra is a large instrumental ensemble typical of classical music, which mixes instruments from different families, including bowed string instruments such as violin, viola, cello and double bass, as well as brass, woodwinds, and percussion instruments, each grouped in sections.

Other instruments such as the piano and celesta may sometimes appear in a fifth keyboard section or may stand alone, as may the concert harp and, for performances of some modern compositions, electronic instruments.

Rockville is a city and the county seat of Montgomery County, Maryland, United States, part of the Baltimore–Washington metropolitan area.

The 2010 census tabulated Rockville's population at 61,209, making it the tenth largest city in Maryland.

Rockville is the third largest location in Montgomery County, after Silver Spring and Germantown.