Page:EB1911 - Volume 23.djvu/296

 music is exactly like the harmonic variety, and the limitations and waywardness of the one are no more archaic than those of the other.

When the resources of later music and the treatment of instruments necessitated the publishing of music in score as well as in separate parts, it became necessary to guide the eye by drawing vertical lines (“bars”) at convenient distances. Hence the term “score” (Ger. Partitur, Fr. partition). These divisions naturally coincided with the main rhythmic groups, and eventually became equidistant. This purely practical custom has co-operated with the great increase of rhythmic firmness necessary for the coherence of those large modern forms which decree the shape rather than the texture of the music, until our notions of rhythm may fairly be described as bar-ridden. And, since the vast majority of our musical rhythms absorb the utmost complexity of detail into the most square and symmetrical framework possible, we are taught to regard the “4-bar period” as a normal (or even ultimate) rhythmic principle, instead of contenting ourselves with broader conceptions which treat symmetry and proportion in time as freely as they are treated in space. It cannot be too strongly emphasized that the bar indicates no universal musical principle. The havoc wrought by mechanical teaching on this point is incalculable, especially in the childish crudeness of current ideas as to the declamation of words in classical and modern music: ideas which mislead even some composers who might have been expected to know better.

As rhythm is contemplated in larger measures, it becomes increasingly difficult to say where the sense of rhythm ends and the sense of proportion begins. The same melody that may be felt as a square and symmetrical piece of proportion in four-bar rhythm if it is taken slowly, will be equally rational as a single bar of “ common time ” (see below) if it is taken very quickly; and between these two extremes there may be insensible gradations. All that can be laid down is that composers are apt to use short bars where they demand constant strong accent, while long bars will imply smoother rhythms. For example, if the scherzo of Beethoven's Ninth Symphony were written in instead of 2 bars, then the passages now marked Ritmo di tre battute would have to appear in 'I time, and so the changes of rhythm would be much more visible on paper. But the tendency to put a strong accent on the first beat of every bar would make this notation an undesirable substitute for Beethoven's, since it would lead to a neglect of the subordinate accents (all of them bar-accents, as Beethoven writes them). The trio of this scherzo shows the opposite case in the fact that Beethoven first intended to write it in 2 time, but, in order to indicate a more tranquil flow at the same pace, doubled the quantity contained in a bar, substituting alla breve bars, each equal to two of the preceding 'I bars. The alteration produced a discrepancy in the metronome marks, which has always caused controversy among conductors, but the facts admit of only one interpretation. It is clear, then, that the only sound theory of musical rhythm will be that in which accent, beat, bar, and even form and 'proportion are relative terms. g V

The kinds of time (i.e. rhythmic groups forming, as it were, invariable molecules in the structure of any continuous piece of music) that are used in all music from the 15th century onwards are nowadays classified as duple and triple, and each of these may be simple or compound. Simple time is that in which the normal subdivision of its beats is by two, whether the number of the beats themselves is duple or triple. Compound time is that in which the beats are regularly divided by three, which three subdivisions are reckoned as subordinate beats. The beats are in all kinds of time reckoned as halves, quarters, 8ths, 16ths or even 32nds of the standard note in modern music, the semibreve: and the time signature placed at the beginning of a piece of music is really a fraction, of which the numerator expresses the number of beats in a bar, while the denominator expresses the size of a beat. Thus I signifies three crotchets in a bar. Compound time is expressed, not by using normal fractions of a semibreve as main beats and dividing them into triplets, but by using dotted beats. A dot after a~ note adds another half to its value, and so not only do 'we obtain the means of expressing a great variety of rhythmic effects (especially quantitative effects of iambic and trochaic character) in all kinds of time, but we are able to use normal fractions of a semibreve as the subordinate beats of compound time. Thus 2 is the compound time obtained by dotting the two crotchets of I time, and is thus totally different in accent and meaning from I time though that also contains six quavers in a bar. The most highly compound times in classical music are to be found in the last movement of Beethoven's Sonata, Op. III. He begins by dividing bars of g into their usual compound time. He then divides the six half-beats of Q time by three, producing §§ (which he incorrectly calls 11), and lastly he divides the 12 quarter-beats by 3, producing 22 (which he calls §§). The special signatures C for 2 time, and C for§ time are the last survivals of the time system of the middle ages (see MUSICAL NOTATION). That complicated system of mood, time and probation was capable of expressing even more highly compound rhythms than our usual time-signatures, though the complexity was in most cases unreal, since the small rhythmic ictus of ecclesiastical polyphony renders little but the general distinction between duple and triple rhythm audible: especially as the more compound rhythms- were not subdivisions but multiples, involving lengths better measurable by an eight-day clock than by human ears. The second Kyrie of Palestrina's Missa L'Homme Armé is one of the rare cases which remain both rhythmic and complex when transcribed in modern score. For genuine articulate complexity the ballroom scene in Mozart's Don Giovanni has never been surpassed. So real are its three simultaneous rhythms of minuet, contredanse and waltz that the persons on the stage actually dance to whichever suits their character. Anomalous measures such as 2 and I time, whether divisible into alternations of 2 and I or not, are aesthetically best regarded not as rhythmic units, but as extreme cases of unsymmetrical phrase-rhythm erected into a system for special effect. They tend, however, to group themselves into musical sentences of reactionary squareness; and the 2 movement of Tschaikovsky's Pathetic Symphony consists of twenty 8-bar periods (twenty-four, counting the repeats) before an unpaired 4-bar phrase is heard in the short coda.. Even the last bar is not odd, though it is the 179th, for the rhythm ends with an unwritten 180th bar of silence. There is, no doubt, a germ of truth in current doctrine as to the fundamental character of 4-bar phrase-rhythms, inasmuch as the human anatomy has a bilateral symmetry with either limb on one side slightly stronger than that on the other. This is probably the basis of our natural tendency to group rhythmic units in pairs, with a stress on the first of each pair; and hence, if our attention is drawn to larger groups, we put more stress on the first of the first pair than on the first of the second; and so with still greater groups, until our immediate and unanalysed sense of rhythm merges into a sense of proportion distributed through time with a clear consciousness of past, present and future. The point at which this merging takes