Cavos was an admirable and painstaking conductor, and his long _régime_ must have greatly contributed to the discipline and good organisation of the opera, both as regards orchestra and singers. His own works, as might be expected from a musician whose whole life was spent in studying the scores of other composers, were not highly original. He wrote well, and with knowledge, for the voice, and his orchestration was adequate for that period, but his music lacks homogeneity, and reminiscences of Mozart, Cherubini and Méhul mingle with echoes of the Russian folk-songs in the pages of his operas. But the public of his day were on the whole well satisfied with Russian travesties of Italian and Viennese vaudevilles. It is true that new sentiments were beginning to rouse the social conscience, but the public was still a long way from desiring idealistic truth, let alone realism, in its music and literature. In spite of the one electrical thrill which Glinka administered to the public in _A Life for the Tsar_, opera was destined to be regarded for many years to come as a pleasing and not too exacting form of recreation. The libretto of Cavos's _Ivan Sousanin_ shows what society demanded from opera even as late as 1815; for here this tragedy of unquestioning loyalty to an ideal is made to end quite happily. At the moment when the Poles were about to slay him in the forest, Sousanin is rescued by a Russian boyard and his followers, and the hero, robust and jovial, lives to moralise over the footlights in the following couplets, in which he takes leave of the audience: Now let the cruel foe beware, And tremble all his days; But let each loyal Russian heart Rejoice in songs of praise. At the same time it must be admitted that in this opera Cavos sometimes gives an echo of the genuine national spirit. The types of Sousanin and his young son Alexis, and of Masha and her husband, Matthew, are so clearly outlined, says Cheshikin, that Glinka had only to give them more relief and finish. The well-constructed overture, the duet between Masha and Alexis, and the folk-chorus "Oh, do not rave wild storm-wind" are all far in advance of anything to be found in the Russian operas of the eighteenth century.