Nor has virtuosity been confined to single instruments. There have been two great virtuosi in orchestration, during this century, who have exercised as great an influence in this complicated and elaborate department, as the others mentioned have upon their own solo instruments. The first of these was Hector Berlioz, the great French master, whose earlier compositions were produced in 1835, when the instruments of the orchestra were combined in vast masses, and with descriptive intention, far beyond anything by previous writers. In his later works, such as the "Damnation of Faust," and the mighty Requiem, Berlioz far surpassed these efforts, every one of his effects afterward proving to have been well calculated. Directly after his early works came the first of that much discussed genius, Richard Wagner, who besides being one of the most profound and acute intelligences ever distinguished in music, and a great master of the province of opera (in which he accomplished stupendous creations), was also an orchestral virtuoso, coloring when he chose, with true instinct, for the mere sake of color; and massing and contrasting instruments in endless variety and beauty. The activity in musical production during the nineteenth century has been so extraordinary in amount and in the number of composers concerned in it, and so ample in the range of musical effects brought to realization, as fully to illustrate the truth of the principle enunciated at the outset of this narrative, namely: That the course of musical progress has been toward greater complication of tonal effects in every direction; implying upon the part of composers the possession of more inclusive principles of tonal unity; and upon the part of the hearers, to whom these vast works have been addressed, the possession of corresponding powers of tonal perception, and the persistence of impressions for a sufficient length of time in each instance for the underlying unity to be realized. As an incident in the rapidity of the progress on the part of composers, we have had what is called "the music of the future"; namely, productions of one generation intelligible to the finer intelligences of that generation, yet "music of the future" to all the others; but in the generation following, these compositions have gone into the common stock, through the progress of the faculties of hearing and of deeper perceptions of tonal relations. Meanwhile there has been created another stratum of music of the future, which may be expected to occupy the attention of the generation next ensuing, to whom in turn it will become the music of the present.