Wagner once compared the conventional connecting passages between the melodic groups of Haydn and Mozart to "the rattling of dishes at a royal feast." Beethoven could not tolerate the traditional commonplaces, which were often mere padding. In these intermediate periods he used phrases which hinted at or were actually closely related to the main themes, and he thus gave the movement the effect of an organic whole, the development of which was as logical as the results that follow from a law of nature. Or he would surprise the hearer by the introduction of a fresh episode of length and importance, although by it the formal rules of the theorist were defied. Even in his second period there are remarkable instances of absolute originality in form as well as in style and conception, as the opening adagio of the pianoforte sonata in C-sharp minor, or the _Con moto_ of the pianoforte Concerto in G. Nor was his manner of the introduction of the themes themselves after the manner of his predecessors; "the glory of the phrase often appeared as it were through clouds that first shrouded it and were then dispelled." He was the greatest master of the art of varying a theme, and his genius ennobled even pianoforte variations, which are too apt, as made by others, to show mere skill and learning, or excite by superficial brilliancy the vain display of the virtuoso who plays simply that he may dazzle. In this species of art is seen the wealth of his ideas as well as the consummate mastery in expression. In the second and the third period of his style there are shining examples of his power in this direction. One kind of variation is peculiarly his own, in which everything is changed, the rhythm, the melody and the harmony, and yet the theme is clearly recognized. Then there are great variations without the name, as the slow movements in the sonata "appassionata" and the Trio in B-flat; the slow movements of the C minor and Ninth Symphonies; the finale of the Heroic.