while the principal subject pursues its quiet course. They are interrupted by the noisy merriment of Don Giovanni and his companions, who are repairing to the merry-making in the casino; the gradual dying away of the song of the retreating guests prepares us for the singularly tender and lovely scene between Zerlina and Don Giovanni, which, contrasted with the preceding duet with Masetto, first clearly shows the dangerous fascination of the seducer. After the inimitably expressed start of surprise at Masetto's reappearance the music alters altogether in character, and Don Giovanni assumes a cordial hospitality and cheerful gaiety which is partly accounted for by the sound of the dance music from the casino; this is made also a musical prophecy of what is to ensue, for the eight bars that are heard are taken from the second of the dances afterwards combined, and Mozart has omitted the two first bars, in order to put the hearer at once in the midst of the dance (Vol. II., p. 154 note). A lively figure for the violin expresses the desire of the three to join in the merriment. The figure is continued when Elvira, Donna Anna, and Don Ottavio appear, and several accompaniment figures are also retained, with important modifications. The minor key for the first time occurring, and the totally different treatment of the orchestra give an impression of a mysterious and gloomy shadow cast upon the noisy merriment of the scene. Leporello, opening a window by chance, sees the masks, and is ordered by his master to invite them to enter. The open window causes the dance music to be more plainly heard, and prepares for what is to follow; this time a minuet is played, which is heard entire, for as long as the window remains open the orchestra is silent, and conversation is carried on parlando. The unusual treatment of this scene prepares the way for the ball; but it is quite as consistent with the adagio which intervenes with surprising and profound effect. {DON GIOVANNI.} (208)