Dido's Lament ("When I am laid in earth") is the closing aria from the opera Dido and Aeneas by Henry Purcell to a libretto by Nahum Tate.
It is included in many classical music textbooks to illustrate the descending chromatic fourth (passus duriusculus) in the ground bass. The conductor Leopold Stokowski wrote a transcription of the piece for symphony orchestra. This is played annually in London by the massed bands of the Guards Division at the Cenotaph remembrance parade in Whitehall on Remembrance Sunday, the Sunday nearest to 11 November (Armistice Day).