Most grievous of such offenders was Rossini, whose gifts of ready and spontaneous melody led him sadly astray. His knowledge of effect was wonderful, but his methods were of the clap-trap order, and although there are admirable points in his work, its appeal was made to popular taste rather than to the musician, and popular taste is a fickle thing. For a while, Rossini, with his sensuous melodies, his whirling _crescendi_, his tricky orchestration, carried Europe with him—into wrong paths; for the taste for such things is not a healthy one, nor can the appetite always be satisfied by a glut of sweetmeats. Besides Rossini there was, as always, a host of imitators who follow their hero at more or less respectful distances, producing works which were pleasant enough but had little or none of the material that makes for endurance, even though the whims, fancies, and tastes of some of our _prime donne_ are responsible for their production, now and again, even in the twentieth century. Opera, indeed, during all this period was again straying from the right lines: again the singers, with their executive abilities, were distracting attention from the equally important dramatic meaning of the works performed. Again the aria and duet were usurping the place of music which should have been defining the stage situation, and conveying to the ear of the auditor a tone-picture to match the scenic representation, and to help to carry on the action of the piece, which, indeed, during these vocal performances suffered much from stagnation. [Sidenote: =Wagner, 1813-1883=] It needed a strong hand to stem the tide on this occasion, and a strong hand was available in the person of Richard Wagner, whose efforts have revolutionized opera to so great an extent that it is unlikely that any great work for the stage will ever be conceived in the future which will not show traces of his influence. For he took no half-measures, but went to the root of the matter, and that in so thorough a way that he really invented an utterly new phase of expression. Until his employment of the kind of music which we call _Melos_ (a continuous stream of melody without definite rhythm, tune, or cadence) music in general, and more especially operatic music, had always, from the time of the early composers of the Monodic School, paid some little regard to form and shape. But Wagner, whose great idea it was that in the rendering of opera the arts of Music, Action, Poetry, and Scenery should stand on an equal footing, was unable to allow attention to be devoted to the music in the very special way in which it was drawn when set forms of song or air were admitted. It overturned the balance which he deemed so desirable, and threw into prominence _one_ art at the expense of the others. [Illustration: WAGNER.] [Sidenote: =The Leit-Motif=]