Elvira herself, with the unbridled passion of her nature, gives vent to her anger in winged words, which are certainly not calculated to produce a comic effect. Donna Anna, on the other hand, and Don Ottavio, persons of high birth and breeding, never so far lose command over themselves as to fall into this hurried speech. The quartet just mentioned is one of the finest instances of the quality and extent of Mozart's genius. The conversation between Donna Anna, Don Ottavio, and Don Giovanni is most unexpectedly interrupted by the warnings of Elvira; the two first are amazed, and uncertain what to make of it, {DON GIOVANNI.} (182) while Don Giovanni, alarmed, seeks by deception to keep them in uncertainty, and to silence Elvira. All this gives rise to a genuinely musical variety of mood tinged with melancholy by the grief of Donna Anna and Don Ottavio. A most prominent feature of the whole is the skilful grouping. Donna Anna and Don Ottavio are inseparable, and form the nucleus of the piece; Elvira and Don Giovanni, though in opposition, are sometimes together, and sometimes in conjunction with the other two. The situation demands that Elvira shall be most frequently isolated, in contrast with the three remaining characters; and as her passionate excitement keeps her in the foreground, she gives the tone to the whole piece, and Don Giovanni is constrained to follow her, while Don Ottavio and Donna Anna only occasionally emerge from their mood of anxious contemplation. A touch of dramatic truth is the adoption by the orchestra and other voices of Elvira's motif to the words--[See Page Image] so that it seems to be the key to the riddle forcing itself on the ear and betraying Don Giovanni's guilt. The motif recurs after all the reproaches, questions, and appeals, and dies away in gentle but pained reproach when the true position of affairs is left unexplained. The suspicion which here enters the mind of Donna Anna prepares the way for the conviction which forces itself upon her that Don Giovanni is the murderer of her father. The grouping of the voices is treated primarily as a means of psychological characterisation. The entrance of Elvira in the second finale gives Leporello a moral shock which brings him musically _en rapport_ with Elvira, and their parts are therefore in correspondence; indeed, towards the end they are in close imitation[157] and opposed to that of Don Giovanni. In the {DON GIOVANNI.} (183) terzet again (Act II., 2), Leporello is first associated with Don Giovanni and afterwards with Elvira, whom he begins by reviling, but who later arouses his sympathy, while Don Giovanni holds aloof from them both. This power of grouping the parts so that they shall serve the purposes of psychological and dramatic characterisation as well as of musical construction, is observable in every one of the ensemble pieces.