The Gaiety Theatre was a West End theatre in London, located on Aldwych at the eastern end of the Strand. The theatre was first established as the Strand Musick Hall (sic) in 1864 on the former site of the Lyceum Theatre. In 1868, it became known as the Gaiety Theatre and was, at first, known for music hall and then for musical burlesque, pantomime and operetta performances. From 1868 to the 1890s, it had a major influence on the development of modern musical comedy. It closed during WWII.
The Wikipedia page is [1]