Roméo et Juliette is a symphonie dramatique, a large-scale choral symphony by French composer Hector Berlioz, which was first performed on 24 November 1839. The libretto was written by Émile Deschamps, and the completed work was assigned the catalogue numbers Op. 17 and H. 79. It is based on Shakespeare's play Romeo and Juliet; it is regarded as one of Berlioz's finest works, and it is among the most original in form. The score is Berlioz's most comprehensive and detailed programmatic piece.