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 12
4 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,[1] 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 9
16. 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.[2] 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
- ↑ Triplets are groups of three equal notes crowded into the time normally taken by two. Binary and ternary subdivision answer every ordinary purpose of musical rhythm, being capable of expressing clear distinctions far more minute than have ever been regulated in speech. It is impossible to pronounce a syllable in less than a tenth of a second; but it is easy to play 16 notes in a second on the pianoforte. (That is to say, musical rhythm continues to be measurable up to the point at which atmospheric vibrations coalesce in the ear as low musical notes!) in a series of such rapid notes a single break twice in a second would have a very obvious rhythmic effect directly measured by the ear. If the broken series were levelled into an even series of fourteen notes a second, the rhythmic effect would be entirely different, though the actual difference of pace would be only 156 of a second. The special sign for triplets is readily adapted to other subdivisions where necessary; but such adaptation generally indicates rather a freedom of declamatory rhythm than any abstruse arithmetical accuracy. Among the worst barbarisms in musical editing is the persistent reduction of Chopin's septoles, groups of 13 and other indeterminable, into mutton-cutlet frills. A natural freedom in performance is as necessary for the minutiae of musical rhythm as it is in speech; but where all but the finest layers fail is in basing this freedom on the superlative accuracy of the rhythmic notation of the great composers.
- ↑ In the critical edition of Palestrina's complete works, vol. xii. p. 177 (Breitkopf and Härtel), the editor has violently simplified it. He is justified in using the ordinary ₵ bars to hold the piece together, and he is not called upon to reproduce the riddles of the original notation; but some secondary time signatures ought to have been added to indicate the strong swing of the tune in its conflicting shapes; and there is no justification, in a full score intended for scholars, in supplanting the true rhythm of the quintus by a rough practical compromise.
