INSTRUMENTATION is the aspect of music which deals with timbre, and with the technical possibilities and characters of instruments and voices. The treatment of the orchestra has for the last hundred years been the most popular branch of the art. Hence the vogue of the narrow term "orchestration." The collo quial word "scoring" is the only adequate name for an art that ought to include all other aspects of timbre and performance, such as chamber-music (q.v.), pianoforte writing and organ registration.
William Wallace, in The Threshold of Music, seems to believe that modern progress in orchestration has produced new cerebral powers. This is a fallacy : listeners or conductors who have become familiar with Richard Strauss's orchestration will vividly imagine the sounds of a page of the master's latest and fullest scoring long before scrutiny has shown more than the main entries and the general type of colouring. But such readers may get nothing but abstract grammatical propositions from a page of Palestrina if they have never heard pure polyphony sung without accompani ment in a vaulted building. The music of each great period has its own proper scoring which sounds well under its proper con ditions. The student should take opportunities of hearing each kind of music well produced ; and he should multiply his experience by reading the scores of all periods, besides those of his own day. An imagination thus trained is obviously useful to conductors. It is not less useful to composers, for it is no mere antiquarian lore but a widely generalised capacity to imagine correctly all kinds of significant musical sounds. Its possessor will never pro duce the woolly scoring of the unimaginative composer who goes by rule ; and if he makes errors of calculation these will be remediable as errors of imagination are not.
Rules are useful in preventing errors of calculation. The only extant treatise on instrumentation that gives correct rules is the posthumous work of Rimsky-Korsakov. Starting with the proposi tion that good scoring is good part-writing, this brilliant and fantastic Russian composer lays down surprisingly severe rules for combining good part-writing with well-balanced orchestral values. At first it seems incredible that any free art could live on such terms ; yet the marvellous purity of Mozart's orchestration supports Rimsky-Korsakov's system in an art a century earlier and far more complex. For there is less wonder that Rimsky Korsakov's colouring should be pure since his ideas never over lap, and his hundreds of illustrations from his own works consist (except for a few scraps of recitative) exclusively of 2-bar or 4 bar phrases that repeat themselves. We shall not learn Mozart's art from this, and rules will not endow us with Rimsky-Korsakov's imagination. Nor was that imagination equal to distinguishing blunders from subtleties in the score of his friend Moussorgsky's Boris Godounov. Much less, then, is it to be trusted when he dis misses Beethoven's orchestration with the remark that the execu tion of Beethoven's ideas is far inferior to their conception. This really means that the narrow cross-section of Beethoven's ideas that comes within the aesthetic range of Russian ballet-music could have been scored more easily and brilliantly by a Russian composer in 189o. Apart from this, Beethoven is doubtless not infallible. But perkiness starves the imagination.
The infinite subtleties of i6th century part-writing are beyond the scope of this article and very remote from the experiences of any instrumental music. But every conductor and every com poser may learn much from Palestrina's and Lasso's devices of producing by part-crossing beautiful progressions that would be crude if the planes of tone were not kept distinct. In all later periods the distinction of planes of tone is a fundamental principle. In the i6th century it enters into these delicate intricacies, and appears more obviously in the rule formulated by the first corn posers for double and triple choirs, viz., that the harmony of each choir must be complete even when all are singing together. Lasso disregards this rule, but its common-sense becomes evident when the choirs are on opposite sides of the building.
Besides gaining a capacity to attack discords boldly, the vocal chorus has undergone a radical change in the treatment of the bass voice when supported by instruments. When the tenor is low but still interior to the harmony, the bass is no longer obliged to go lower, but is free to sing in its upper register, crossing freely above the tenor but relying on instruments which double it an 8ve lower as the true bass. Bach and Handel never once cross the bass over the tenor in any other way; the tenor in such places never gives the true bass. And Bach's so-called unaccompanied motets thus show in every line that they were conceived as sup ported by at least an instrumental bass. In fact, unaccompanied choral writing practically disappears from classical music between Palestrina and Schubert. It appears modestly in part-songs, and is first taken fully seriously by Brahms; though some older conductors of choral societies honourably kept up its tradition.
The basis of the continuo orchestra was, as now, the string band, an instrumental chorus of first and second violins, violas and viol oncellos, supported an 8ve lower by double-basses which are never independent. Wind instruments did not form a complete mass of harmony but stood out against the strings in double or triple threads of each timbre, except when (as often in Handel) they doubled the strings. Flutes were used much more in their lower registers than we think fit in modern orchestration. In the organ-loft of a vaulted building low flutes are more effective than in ordinary concert-rooms. The ordinary flute is called traverso. The term flauto, with the use of the treble clef on the bottom line, indicates the flute-a-bec, a kind of flageolet, with rather a higher range. Bach uses pairs of each kind in the Matthew Passion but not in the same movements.
Oboes are also used in threes or pairs, and the ordinary oboe alternates with a variety a 3rd lower, the oboe d'amore, with the bell (and therefore the tone) of a cor anglais. Strauss has revived it. The real cor anglais figures in Bach's orchestra as the oboe da caccia or the taille. Some authorities tell us that one or other of these was not an alto oboe but a tenor bassoon. It is easier to relabel a museum specimen than to rewrite the whole of Bach's oboe da caccia music.
Bassoons hardly ever emerge from doubling the bass. The Quoniam of Bach's B minor Mass is a bass solo accompanied by a horn, two bassoons and continuo. It would be delicious if we could find proper acoustic conditions for it and could handle the con tinuo discreetly enough. A great moment is the rising of the spirit of Samuel in Handel's Saul, where the bassoons are as ghostly and awesome as the prophet's message. In large enough numbers they would also astonish us in Handel's scoring of the "thick darkness" in Israel in Egypt. Handel, whose oratorio performances were on a large scale, must have had more reed-tone than string-tone in his orchestra; for he often had 20 oboes and 20 bassoons. Multi plication greatly mellows the tone of an instrument; and we, who seldom hear more than 4 oboes in unison, even in Mahler's 8th symphony, must not hastily judge our ancestors on this point.
Trumpets and horns, not being provided with modern valves, could produce only the natural harmonic series of the key to which their length of tube was set. That series does not close up into anything like a scale until the 8th harmonic. Accordingly trumpet ers devoted themselves to acquiring extraordinary command of the delicate distinctions of high lip-pressures (embouchures) be tween the 8th and 20th harmonics. A long mouthpiece, with a little play in its adjustment, enabled the trumpeter to correct the out-of tune nth, r3th and i4th harmonics. (This secret was already forgotten by 1785, so that Burney, describing the Handel Cen tenary Festival, tells us that whenever the G and G#, alternately represented by the r r th harmonic, were heard in "The trumpet shall sound" displeasure was seen on every countenance.) Hum bler players called themselves Principal-bldser and produced the lower notes to which the tight-lipped clarino-player could not descend. Horn-players developed a similar hazardous technique of high notes. In modern performances special training and special instruments are required for early r 8th century trumpet and horn music. A modern tendency to strain all instruments up to high notes has facilitated this revival. Trombones, when they occa sionally appear in continuo orchestration, are treated exactly like choral voices, and are, indeed, mainly used in unison with the chorus. A soprano trombone at first completed the group but Bach already had to replace it by some kind of slide-trumpet (corno da tirarsi).
Bach's full orchestra consists, then, of the string band (prefer ably larger than he ever had) oboes (ordinary or d'amore) in pairs or' threes, flutes or flutes-a-bec in pairs or threes, bassoons (taken for granted) in unison with the basses, three trumpets (two clar ini and one principal) three horns (not often used together with the trumpets) and a pair of kettle-drums. If the string band is large the wind parts, other than the trumpets, should be doubled, trebled, or (in festival performances) multiplied. The organ sup plies the continuo in choruses, and the harpsichord supplies it in solo movements. The pianoforte is really (as Philipp Emanuel Bach already urged) better than the harpsichord, if only the player will avoid a self-assertive touch.
The orchestral combinations of solo movements range from Handel's perfunctory tutti unison to Bach's and Handel's richest schemes. Instruments obsolescent from incompatibility or feeble ness live awhile in the arias and recitatives, protected from com petition with the orchestra; and so we learn from Bach's Passions and Tracer Ode the use of the lute and viola da gamba, and from Handel's Alexander Balus the use of the theorbo, a large double necked lute. Each movement has its own scheme of instrumenta tion as a set pattern which cannot change while the movement lasts.
The scheme of a chorus with independent full orchestra is in three planes of tone. These planes do not interfere with each other, and each plane has variants of the same harmonic scheme which would produce appalling collisions if all were projected on to a single plane (say, in an arrangement for two pianofortes). The principal plane is that of the voices. Above it, mostly higher in pitch, all the instruments that are not doubling the bass flourish with more rapid detail than the voices. Behind, and supporting the whole, is the continuo which moves more slowly than the chorus. The bass is common to all the planes, though it is en livened by instrumental details. The results of this scheme, re alised by competent execution under scholarly guidance, are as true in our age as they were when Bach and Handel wrote. Schol arship must show us the right conditions for performance, but it need not recover too precisely the actual original conditions. An old man who had been a chorister under Bach at Leipzig once told Wagner's teacher, Weinlig, how Bach's cantatas were per formed. His account was, "It went atrociously and we always got a flogging afterwards." Symphonic Orchestration.—Gluck (q.v.) laid down one of the cardinal principles of symphonic as well as dramatic orches tration when he said that instruments ought to he used according to dramatic vicissitudes. This means that for Gluck it is neither sufficient nor often possible to use them according to a set pattern. Another cardinal principle results from the disappearance of the continuo. This first happened merely by neglect, as the severe training needed for it repelled a generation of musicians excited by non-polyphonic styles. But mere neglect soon passed into a disposition to make the orchestra provide its own continuo. If old music sounded hollow without a continuo, why should not new music contrive better? This at once put many instruments into categories unrealized by Bach and only sporadically realized by the eclectic Handel. An instrument could now have two values: one, the old cantabile function ; the other a capacity to provide unobtrusive notes for the background. Holding-notes for the horns revealed a wonderful beauty and usefulness in this way, with all a singer's power to swell and diminish the sound.
The bassoons became the hardest worked wind instruments in the early symphonic orchestra, for they could do everything re quired of continuo-work, from doubling the bass to supplying the many notes the natural horns could not reach. Their tone, so beautifully if unwittingly described in The Hunting of the Snark as "meagre and hollow but crisp, like a coat that is rather too tight in the waist, with a flavour of will-o'-the-wisp" had a most useful capacity for vanishing; and "too tight in the waist" is a very apt description of instruments which, like the bassoon and the viola, show in their half-veiled tones the results of a compro mise between the dimensions proper to their pitch and the prac ticable stretch of human hands.
The viola had at first a curious position in the early symphonic style. That style was so unpolyphonic that the viola could for a long time find nothing to do but to double the violoncello in the upper octaves as the basses double them in the lower. The result is so good that in early symphonies it is carried out mechanically even where it takes the violas above the second violins. But Mozart uses this primitive device with full imaginative insight in mature works where he hardly less often divides the violas into two independent parts.
The trumpets of the symphonic orchestra have become degraded to the fanfares and signallings of the Principal-blhiser. The clarino player was finally ousted by players of a cheap substitute called the clarinet, which could play high trumpet parts with ease, if with rather a vinegar tone. But the clarinet had a wide compass; these trumpet-sounds are its worst. Below them it had a rich can tabile octave, and below that a few rather dull notes; and below these a coldly mysterious and reedy lowest octave, the chalumeau register. The dull middle notes proved astonishingly useful for continuo purposes; they are higher than the bassoon can attain without self-assertion, and they are not limited like the horn notes. Gluck uses the clarinet only in this neutral region; and even Mozart gives the instrument nothing better when the orchestra is in the key of D. This primitive treatment survives as late as Beethoven's 2nd Symphony, and revived by him in quite a late work, the fugal overture, Zur W eihe des Houses (op. 124) .
But when Mozart uses clarinets in the keys of A major, E major, E flat and B flat he reveals the clarinet as richer and more re sourceful than any other wind instrument. The chalumeau octave is deliciously nutty in arpeggios, and dramatically hollow in sus tained notes. The cantabile octave is magnificent (see the trio of the minuet of the great E flat symphony, for its contrast with echoes on the flute and with low arpeggios on the second clarinet). The military high notes (or "fife sounds") Mozart does not care for. Beethoven's view of the clarinet is less sympathetic than Mozart's, his idea of its cantabile register being just a tone too high. Schubert understands it perfectly.
The oboe can never efface itself. Run through the individual wind-parts of some such encyclopaedic score as Wagner's Meister singer and you will be astonished at the unfailing beauty of the oboe parts and at the large tracts of drudgery in the excellent, uncomplaining clarinets.
The flute has no power in its lower octave and blends with other instruments in none, except, paradoxically, with extremely high Bach-like trumpet notes (if the experiment were ever tried). But in its top octave (from A to A) it is a very adequate and euphon ious treble to the wind-band, and gains greatly by doubling. Haydn hardly ever writes his orchestral flutes high enough and often seems to expect low notes to be heard under conditions that would not have satisfied Bach. It is possible that his long period of ex periment at Esterhazy did him less good than he or historians have thought. His Esterhazy symphonies show that he had a prim itive orchestra diversified by astonishing solo players. He was able at Esterhazy to produce horn-passages that would astonish Bach. But in the world outside he found that orchestras, though better in the rank and file, were seldom troubled by virtuoso mem bers. In his last symphony the theme of the finale is a typical and easy horn tune, but he dare not give it to the first horn of Salo mon's London orchestra except under cover of a tutti ! All his mature scoring is full of strokes of genius but deeply marked with signs of disillusion.
Errors of imagination do not exist in Beethoven's art ; and only a school of criticism by rule of thumb would suppose that they did. Compared with Mozart's, Beethoven's scoring is rough, re dundant and capricious. But Beethoven's ideas are not Mozart's and can be expressed neither in Mozart's nor in Wagner's scoring. When critics tell us that bars 5-8 of the first movement of Bee thoven's 8th Symphony are badly scored, all they mean is that to let two oboes and a flute crowd in upon a quiet phrase in the clarinet is not a proper way to score the first fateful appearance of a Wagnerian leit-motif, which may not be heard again for an hour. But it is an admirably dramatic and symphonic way to score a formal phrase which is going to be shouted at the top of the full orchestra immediately afterwards. The conductor need only say four words to the oboes, "Let the clarinet through," and the passage becomes perfectly clear. But it is already intelligible with out any such precaution, and only bad playing can spoil it.
The symphonic orchestra which suffices for Beethoven, and for Brahms two generations later, consists of strings, pairs of flutes, oboes, clarinets, and bassoons, one or two pairs of horns, a pair of trumpets and kettledrums. Trombones, reserved for climaxes, are used in spacious 3-part harmony, and Beethoven requires them in three sizes, alto, tenor and bass. For lack of the alto trombone many of Beethoven's top notes must nowadays be low ered ; and then our smart young orchestrators blame Beethoven for his ill-balanced chords. The full wind tone is extended up wards by the dangerously shrill piccolo, and downwards by the contrafagotto which gives the bass a richness without asserting itself. The big drum, cymbals and triangle are called "Turkish music" and, when used at all by Beethoven, are used according to Viennese ideas of Turkishness. Beethoven's intentions, whatever we may think of their execution, cover the whole field of sym phonic art; and it is to dramatic orchestration that we must look for any addition to his range of thought.
And yet there is no limit to the refinement of dramatic orches tration whether in Mozart or Wagner. The gradations that a symphonic composer uses in zo bars must be spread over a hun dred in any continuous part of an opera, even on Mozart's scale. Here we already have a reason why opera should encourage very delicate gradations. Wagner's scale is given by the three minutes of the chord of E flat at the beginning of Das Rheingold; but still more significant is his management of a tensely emotional quarter of an hour with no more orchestra than strings and two horns, without double-basses, in the first act of Die Walkiire. His enlarge ments of the orchestra all have an ultimate effect of purifying the timbre and so removing complications from the method of scor ing. There was nothing new in large orchestras : both Mozart and Beethoven had rejoiced in performances with double wind; and in Wagner's early Dresden days Spontini requisitioned "douze belles contrebasses" for the performance of his operas. The experienced Wagner of Bayreuth is contented with eight.
A great stimulus was given to all orchestration by the inven tion of ventil trumpets and ventil horns. When these instruments thereby acquired a complete scale the aesthetics of all brass in struments needed reconsideration. Unimaginative composers of course saw no difficulty. A trumpet penetrates everything else like a red-hot poker, so why not give it the melody in every tutti? Wagner thought otherwise ; he felt that brass tone was coarse un less it was used in large harmonic masses, and he accordingly in vented new brass instruments to make the masses complete and coherent. Meanwhile he took his wind instruments in threes in stead of twos. Already in the comparatively simple scores of Der Fliegende Hollander and Lohengrin this greatly clarified the col our-scheme. Half the art of scoring for wind instruments in the classical symphonies consists in making the best of the fact that instruments of contrasted tones will not make homogeneous triads when taken in couples. In Tristan and Isolde the threefold arrangement (two oboes and cor anglais; two clarinets and bass clarinet) adds its advantages to the maturest Wagnerian harmony, with a polyphony as profound as that of Beethoven's last quar tets. In the tetralogy of Der Ring des Nibelungen Wagner takes his wind groups in fours, and introduces his new brass instruments. They originated in the bass-tuba which had come to replace the grotesque ophicleide and the still more primitive serpent as a bass to the trombones. These makeshifts had served Mendels sohn's purpose and failed to serve Berlioz's. The tuba could put an imposing bass below the trombones. Its tone is fat and puffy whereas that of the trombone is red-hot. A sensitive ear may notice, and a wise ear may refuse to notice, that the tuba is put ting a black line below the red. But Wagner saw the possibility of a new aesthetic value here ; and so in his tetralogy five tubas rang ing from contrabass to high tenor show as clear a contrast from trombones as oboes from clarinets (Rimsky-Korsakov utterly fails to grasp this point) .
The composers, having learnt new powers from such enlarge ments, can henceforth use these powers without extra apparatus. The orchestration of Die Meistersinger is the most complex in all Wagner, just because it is written for Beethoven's orchestra plus one tuba and a harp, and, of course, the now ubiquitous ventil horns, the most perfect of all continuo-players. In Parsi f al the extra tubas are abandoned but the remaining contrabass-tuba has permanently won its independence of the trombones.
It seems paradoxical to leave Berlioz out of account in a history of instrumentation. Yet, short of a detailed appreciation of his individual strokes of genius, all that can be said of him is that he drew attention to the subject in an epoch-making but capricious treatise, and that he achieved all that was possible to a highly imaginative musician who happened to hate polyphony. And that is more than some critics might expect. But it cannot have much direct influence on more ordinary musicians.
When we have dismissed all such precious nonsense, several real phenomena remain. New harmonic ideas, such as multiplanar harmony, depend inextricably on instrumentation as surely as did the classical grammar of counterpoint. Less important is what Richard Strauss has called al fresco orchestration. This means a perception that there is not only safety in numbers, but a high aesthetic value in the average result of sixteen wildcat attacks at a passage that no individual can play properly. It is doubtful whether that is the real reason of the splendour of such passages. For one thing, the splendour is enhanced by rehearsal, and in the best orchestras the players eventually learn such passages fairly accurately.
Mahler made a systematic study of the possibilities of very large orchestras; almost a quarter of the size of that of our Crystal Palace Handel festivals, but with music specially written for them. His 8th Symphony is a choral symphony requiring at least 75o performers, and going much more satisfactorily with 1,000. Berlioz never really contemplated anything larger. Such propositions are not decadent ; they are severely disciplinary and require an imagination of the highest efficiency. On a large scale most orchestral colours fade ; especially horns, which must be greatly multiplied if they are to tell.
More fascinating to most artists, and more practical in the present lean years, are the aesthetics of small groups and cham ber-orchestras. But this is a subject which cannot be pursued here. It is as much as a young composer's prospects are worth to come before modern critics without a new aesthetic system of his own invention. But a general article cannot deal with such private affairs. (D. F. T.)