We have already considered briefly the various ways in which Beethoven expanded the structural elements of the sonata, and now it may not be amiss to examine for a moment the æsthetical characteristics of his pianoforte works in sonata form. In the early sonatas he began with the four movements which others had almost wholly reserved for the symphony. The scherzo in sonata and symphony was peculiarly his invention. To be sure the name is older, and was used in describing secular songs in the 16th century as well as for instrumental pieces in the 17th. But the peculiar quickly moving number with its piquant harmonies and rhythm and its mocking, grotesque or fantastically capricious spirit is the musical thought of Beethoven. At times the scherzo assumed gigantic proportions as in the Third, Fifth and Ninth Symphonies, and in the sonata Op. 106. Before his day the imagination of the composer had not had full play; it was more or less hampered by conventionalities, by the necessities of the men dependent on princes' favors. The expansion of a great idea in the sonata is found first in his works. Deep feeling, passionate longing took the place in the slow movement of simple melody with its unmeaning and elaborate ornamentation. He introduced the recitative with thrilling effect. Although the breadth of the thought in different movements is majestic even to awe, all phases of human feeling are expressed. Strength and delicacy, gloom and playfulness are found side by side. The sonata form with Beethoven was the means of the full development of all the expressive elements in music. These considerations are likewise true of his piano and violin sonatas, trios and concertos, the most prominent of which are the so-called Kreutzer Sonata, for piano and violin, trio in B flat, violin concerto, and piano concertos in G and E flat. These famous works stand foremost in their respective branches, but to dwell on their individual characteristics would exceed the limits of this article.