Sculpture is motion caught in a moment of perfection. Music is motion always in perfection. This rhythm exists also in literature and the other arts. Poe would be nothing without it; Whitman uses it in long swelling undulations which are sometimes almost indistinguishable; the composition in a great painting is a rhythm; the Apollo Belvedere is all rhythm. But in music rhythm is a physical, moving property; rhythm in being, not rhythm caught in a poise. The possibilities of rhythmic play in music far exceed those in poetry, for in the latter the sense or meaning would be clouded by too much rhythmic complication. It would be impossible to do in poetry, for example, what Beethoven does at the beginning of a movement in one of his string quartettes,[2] where the ’cello, entirely alone, repeats one note fifteen times in two rhythmic groups; there is no melody and no harmony--merely one reiterated rhythmic sound. It is also impossible for poetry to present three or four different rhythms simultaneously, as music often does; nor can poetic rhythms carry across a complete rhythmic disruption whose whole æsthetic sense lies in its relations to a permanent rhythm which it momentarily violates, as is the case in the first movement of Beethoven’s Third Symphony. In short, rhythm in music has a diversity, a flexibility, and a physical vigor quite unparalleled in any other art. Melody in music consists in a sequence of single sounds curved to some line of beauty. Whereas rhythm is conceivable without any intellectual quality,--as a purely physical manifestation,--melody implies some sense of design, since it progresses from one point in time to another, and without design would be merely a series of incoherent sounds. In this design rhythm plays a leading part, and the themes having the most perfect balance of rhythms are the most interesting. Examples of diverse but highly coördinated melodies may be found in the slow movement of Beethoven’s pianoforte sonata, Opus 13, and in Brahms’s pianoforte quartette, Opus 60, the synthetic quality of which is like that of a finely constructed sentence. Melody, being design, gives conscious evidence of the personality of its creator. Schubert, for example, is like Keats and represents the type of pure lyric utterance. Bach, on the contrary, is essentially a thinker, and his melodies are full of vigorous and diversified rhythms.