HARMONY

(1) T h e E v o l u t i o n o f t h e H a rm o n i c S e n s e .- T h e p ra c t ic e of com b in in g so u n d s of d i f f e r e n t p i tc h is d e s c r ib e d b y th e tw o te c h n ic a l te rm s : harmony a n d counterpoint. T h e re is n o t in f a c t a wh o lly logical s e p a r a t io n b e tw e e n th e s e tw o fo rm s of d e f in it io n , b u t th e m a in d i s t in c t io n s w h ic h tu e y em b o d y c a n be u n d e r s to o d w i th f a i r a c c u r a c y if h a rm o n y is t a k e n to m e a n a m o re v e r t ic a l c o n s id e r a t io n of c om b in e d n o te s , while c o u n te r p o in t d e als w i th a m o re h o r iz o n ta l a s p e c t of th em . C o u n te rp o in t is th u s a w e a v in g of melodic s t r a n d s of th o u g h t , in w h ic h th e c om b in a t io n s of n o te s t h a t ar is e in c id e n ta l ly h a v e o r h a d a co n s id e ra b le p a r t of th e i r m e a n in g a n d ju s t i f ic a t io n in th e melodic logic of th e p r o gre s sions which give rise to th em . T h e v e r t ic a l c om b in a t io n of s o u n d s is n o t , c o n t r a p u n ta l ly sp e a k in g , a n e n d in itself. In d e e d , i t wo u ld h a rd ly be to o m u c h to s a y t h a t th e r e is 110 t r a d i t io n a l c om b in a t io n of n o te s in e x is ten c e which, a n a ly s e d in to i t s s im p le s t te rm s a n d t r a c c d th ro u g h i t s h is to r ic a l e v o lu t io n , c a n n o t be d e r iv e d in th e la s t r e s o r t f rom th e in c id e n ta l e n c o u n t e r s of e s s e n t ia l ly melodic ideas. E v e n th e in te rv a l of t h e o c ta v e is n o e x c e p t io n t o th i s r u l e ; fo r a l th o u g h th i s in te rv a l re p re s e n ts , f rom th e h a rm o n ic p o in t of view, th e m o s t f u n d a m e n ta l a n d c o n v in c in g c o n so n a n c e t h a t e x is t s , th e r e is l i t t le d o u b t t h a t i t was u s e d in tu i t iv e ly fo r th e re in fo rcin g of a s ingle melodic line long before i t s m a th em a t ic a l a n d p h y s ic a l s im p l ic i ty wa s in te l le c tu a l ly u n d e r s to o d . E q u a l ly p r o b a b le is i t t h a t t h e use of c o n s e c u t iv e fo u r th s a n d f if ths a ro s e in th e f ir s t pla c e f rom a de s ire to p ro v id e th o s am e me lodic m a te r ia l fo r voices of d i f f e r e n t p i tc h . In te l le c tu a l a n a ly s is of th e s e p h e n om e n a h a s s u b s e q u e n t ly r e la te d th em to th e o r ie s of in t r in s ic h a rm o n ic c o n so n a n c e , a n d m a n y a b le a n d in g e n io u s e x p la n a t io n s h a v e b e en g iv e n of t h e s till mo re c om p l ic a te d im p r e s sions which h a v e since s a tis f ied th e a u r a l in tu i t io n s of mu s ic ian s . B u t th e g ulf b e tw e e n th e logical science of a co u s t ic s a n d th e em p i r ic a l a r t of h a rm o n y h a s n e v e r b e en c o n v in c in g ly br id g e d , a n d th e c au s e of th i s fa i lu re to m a k e s cience a n d a r t coinc ide seems to lie u n d o u b te d ly in th e f a c t t h a t h a rm o n y is la rg e ly th e s e c o n d a r y p ro d u c t of c om b in e d melodies. Whatever be the proper view of the dim historical beginnings of harmony, it is at least certain that melodic combination provides the only aesthetic explanation of many of the most important elements in the harmonic systems to which music has from time to time attached itself. It is this fundamentally contrapuntal derivation of so much of our music which makes the analysis and definition of harmony as such a task which is not only highly complex, but which also admits of many legitimate divergences of view. Just as counterpoint is much more than a purely horizontal technique, in that the incidental clashes of its melodies must also obey moro or less rigid conventions of harmonic consonance, so harmony, though conceived primarily as a system of vertical associations, y et finds much of its logic in the precedent or subsequent behaviour of individual parts. Even with regard to so established a convention as the common chord, the chord, that is, which consists of a fundamental note sound cl together with its third and fifth, the fact that this formula has for so long been accepted as a stable point of rest does not alter the historical truth that at least one important element in it, the third, was in the first place contrapuntally approached and exploited, and did not for a considerable time satisfy the then prevailing ideas of consonance. Considerations such as these must be constantly borne in mind in the discussion of harmonic evolution. The art of harmony derives its general orientation from historical tradition and experience. It is the study of aural conventions of consonance, some of which may agree with scientific theory, while others certainly do not. The pivots of harmonic thought are those combinations of notes which enjoy varying but accepted degrees of stability in the technique of their particular environment. Expansions of the system generally arise through the comparatively exceptional behaviour of single parts. Chords which are accepted as stable are classified as concords. Unstable chords are those in which not every element is accounted to be melodically at rest. These are called discords. It is a natural feature in the evolution of the harmonic sense that these two terms, concord and discord, are always slowly but steadily shifting their ground. What was initially a discord becomes by reiterated use a more stable convention, with reference to which other and more exceptional combinations are in turn discovered, and so, theoretically at least, ad infinitum. This does not one whit invalidate the meaning and reality of concord and discord with respect to their fundamental values in the art of musical e x pression. What history has to tell us is that the story of harmony is the story of a gradual fixing of relations, a slow growth of conventions, and in this flux of impressions there is no break. The Greeks were theoretically conscious of the mathematical relations on which certain harmonic conceptions can be made to rest, but it does not appear that they actually used these discoveries for artistic purposes. Their scales were melodically conceived, and the various intervals which these scales offered were not regarded as elements capable of harmonic combination. The artistic purpose of variations of pitch was melodic expression, and this purpose remained paramount throughout the early history of the music of which we have record. The scales characteristic of the various ecclesiastical modes, whether derived or modified from Greek sources, were also, both in theory and practice, exclusively melodic in conception. So far as we are able to gather from the fragmentary evidence of these early centuries, probably the only device which can be prophetically interpreted as involving the possibility of what we now define as a harmonic consciousness, was the use of a drone. W hether this drone came from a pipe of definite pitch or from the more ambiguous sound of a drum, it served as no more than a background for tho melodic line. It did not combine with it. The earliest system in which something approaching a latent sense of harmony is clearly indicated, is that known as ' D iaphony ' (see D ia ph o n ia ) or Organum (q.v.), of which examples are found in the 10th century. This music consists for the most part in successions of perfect fifths and fourths, sometimes built into a three-part structure whose external dimensions are mainly octaves. The following examples arc from Musica Enchiriadis, and have been variously ascribed to Hucbald or Otger: It is important to observe that a t this time only the fourth, fifth and octave could be used harmonically without qualification. Other intervals were passing and unstable effects which had to be approached and quitted contrapuntally. Even a century later, Guido of Arezzo defines Organum as consisting essentially of successions of these primitive consonances. There was, however, almost contemporary with Guido, a more elaborate system called ' Discantus ' (see D e sc a n t ), which involved a simultaneous performance of distinct melodies, tho combination being made comparatively tolerable by certain modifications of discordant notes. This system is described by Franco of Cologne (11th cent.), and if to this we add the early attempts a t Canon, whether deliberate or accidental, we have the genesis of that wonderful growth of polyphony to which music owes so many of its major traditions. ' Sumer is icumen in ' is an outstanding example of canonic organisation as the 13th century understood it, and in this same century Marchetto of Padua gives examples of combined melodic progressions which are remarkably independent. <