Arlecchino, oder Die Fenster (Harlequin, or The Windows, BV 270) is an opera by Ferruccio Busoni, with a libretto in German written by the composer in 1913. He completed the music for the opera while living in Zurich in 1916. It is a number opera written in neo-classical style and includes ironic allusions to operatic conventions and situations typical of the late 18th and early 19th centuries. It even includes a parody of a duel. This would make it about 105 years old.