KHYTHM. 115 RHYTHM. time. Regarded as perception, it is a series of auditory or tactual (never of visual) sensations, which recur at regular intervals and sliow a regu- lar variation of intensity. lu other words, our interpretation of rliytluu as a perception simply translates the objective dclinition into subjective terms. There are, however, certain phenomena of the rhjtlimical consciousness which <ie led some psyoliologists to accept the other view, that rhythm is a kind of emotion. (1) If we subject an observer to a series of regularly recurring and similar sounds, we find (within definite time lim- its) that in the majority of cases the series is apprehended as rhythmical. The most familiar instance is that of listening to the ticking of a clock ; the beats of the pendulum are heard, not as tick, tick, tick, but as tick, tick, tick-, tick, etc. (2) We can produce the effect of rhythm not only by changing the objective intensitj' of regularly recurring stimuli, but also (o) by changing their duration, {h) by changing the interval between them, and (c) by changing their quality. Tliat is to say, the intensities may remain constant throughout, and 3'et ( if some one of these three variations is introduced into the series) the ob- server will have the illusitm of intensive fluctua- tion, and will therefore be constrained to hear the series as rhythmical. (.S) There is a strong tendency to 'express' rhytlim, to accompany a Example 4. first beat of every bur 1ms an accent, while in examples 2 and 3, although every bar retains its own accent, there is no special accent or em- phasis at the Ijeginning of the rhythmic figure. Accent llius deals with the notes of a single ineus- urc; rhytlim with groups of notes extending over one or (generally) more measures. .Music be- comes intelligible only when these larger rhyth- mic divisions are clearly grasped. A cultivated ear soon tires of constant regularity of rhythm. To avoid monotony, composers resort to various means of breaking the rhythm, such as inserting an odd bar between the regular mnnher of burs comiKising a rhythmic group, alternating two- bar with three-bar rhythms, or making the weak ending of a phrase coincide with the strong be- ginning of a new phrase (thus really causing the elision of a bar) . The only simple rhythms are those consisting of a group of notes filling two or three measures (duple and triple rhythm). All rhythms extend- ing over more than three bars are compound. Thus every four-bar rhythm can be resolved into two groups of two bars each. A six-bar rhythm may consist of two groups of three bars each or three groups of two bars each. The Scherzo of Beethoven's Ninth Si/mphon!/ (Ex. 4) begins with a theme in (|uadruple rhythm (two groups oi duple rhythm). series of rhj'thmical sounds by movements of head, foot, or band. Rhythm in Music. The regular recurrence of tone-groups in which the individual notes are symmetrically arranged according to accent and time-value. Rhythm is entirely independent of melody or harmony '(qq.v.) and can, therefore, be indicated by notes without reference to pitch. Example 5. The following examples illustrate this: While every bar retains its own accent (marked — ), there is a particular emphasis (marked =) upon the first and fifth bars (the beginnings of the rhythmic group) and a less emphasis (marked =) upon the third and sixth bars. The effect produced is the same as if the phrase were w-ritten in more moderate tempo as follows : Example 1.— Polonaise, 3 4 After a number of bars Beethoven changes this •L^' Example 2.— Fandango. 3 8 Example 3 —Beethoven 6 ^Symphony No. 7;. 8 J mrnmrn m mmmmm m d mm J/ m m m m l^ In the first example the characteristic rhythmic quadruple to triple rhj-thm: Example 6. figure is contained within the limits of a single which produces the following effect: Example 7. measure; whereas in the other two examples it A loose u.se of language has created a _ great fills two measures. It is evident from this that deal of confusion in regard to the meaning of rhythm is not sj-nonymous with accent; for the the term rhythm. The word is often carelessly
