The early 17th-century attempts at their independent use and
characterization are historically interesting, but artistically
almost barbarous. Sometimes they achieve rare beauty by
accident. Heinrich Schütz’s Lamentatio Davidi is written for a
bass voice accompanied by four trombones and organ. The trombone
parts are on exactly the same material as the voice, which
in fact forms with them a five-part fugue-texture. The effect is
magnificent, and admirably suited to the dignity of the trombone.
Moreover, the opening theme is formed of slow arpeggios; and
the more modern harmonic elements, though technically chromatic,
consist, from the modern point of view, rather in swift
changes between nearly related keys than in chromatic blurring
of the main key. All this, especially in a writer like Schütz,
who is saturated with every progressive tendency of the time,
seems to point to a deep sense of the appropriate style of
trombone writing. Yet, so insensible is Schütz to the euphony
of his own work, that he proposes, as an alternative for the first
and second trombones, two violins an octave higher, the other
parts remaining unaltered! Imagination boggles at the vileness
of this effect.
The chief work done in instrumentation in the 17th century is undoubtedly that of the Italian writers for the violin, who developed the technique of that instrument until it proved not only more resourceful but more artistically organized than that of the solo voice, which by the time of Handel had become little better than an acrobatic monstrosity. In the art of Bach and Handel, instrumentation, as distinguished from choral writing, has attained a definite artistic coherence. Choral writing itself has become different from what it was in the 16th century. The free use of discords and of wider intervals, together with the influence of the florid elements of solo-singing, enlarged the bounds of choral expression almost beyond recognition, while they crowded into very narrow quarters the subtleties of 16th-century music. These, however, by no means disappeared; and such devices as the crossing of parts in the second Kyrie of Bach’s B Minor Mass (bars 7, 8, 14, 15, 22, 23, 50) abundantly show that in the hands of the great masters artistic truths are not things which a change of date can make false.
But the treatment of instruments in Bach and Handel has a radical difference from that of the art which was soon to succeed it. It has precisely the same limitation as the treatment of form and emotion; it cannot change as the work proceeds. Its contrasts are like those of an architectural scheme, not those of a landscape or a drama. It admits of the loveliest combinations of timbre, and it can alternate them in considerable variety. Modern composers have often produced their most characteristic orchestral effects with fewer contrasting elements than Bach uses in his Trauer-Ode, in the pastoral symphony in his Christmas Oratorio, in the first chorus of the cantata Liebster Gott, wann werd’ ich sterben, and in many other cases; but the modern instrumental effects are as far outside Bach’s scope as a long passage of preparation on the dominant leading to the return of a first subject is beyond the scope of a gigue in a suite. Bach’s conception of the function of an instrument is that it holds a regular part in a polyphonic scheme; and his blending of tones is like the blending of colours in a purely decorative design.
Those instruments of which the tones and compass are most suitable for polyphonic melody are for the most part high in pitch; a circumstance which, in conjunction with the practice (initiated by the monodists and ratified by science and common sense) of reckoning chords upwards from the bass, leads to the conclusion that the instruments which hold the main threads in the design shall be supported where necessary by a simple harmonic filling-out on some keyed instrument capable of forming an unobtrusive background. The chords necessary in this part, which with its supporting bass is called the continuo, were indicated by figures; and the evanescent and delicate tones of the harpsichord lent themselves admirably to this purpose where solo voices and instruments were concerned. For the support of the chorus the more powerful organ was necessary. It is in the attempt to supply the place of this continuo (or figured bass) by definite orchestral parts that modern performances, until the most recent times, have shown so radical an incapacity to grasp the nature of 18th-century instrumentation. The whole point of this filling-out is that, the polyphonic design of the main instruments being complete in itself, there is no room for any such additional inner parts as can attract attention. In the interest of euphony some harmonious sound is needed to bridge the great gap which almost always exists between the bass and the upper instruments, but this filling out must be of the softest and most atmospheric kind. Bach himself is known to have executed it in a very polyphonic style, and this for the excellent reason that plain chords would have contrasted so strongly with the real instrumental parts that they could not fail to attract attention even in the softest tones of the harpsichord or the organ, while light polyphony in these tones would elude the ear and at the same time perfectly bridge over the gap in the harmony. There seems no good reason why in modern performances the pianoforte should not be used for the purpose; if only accompanists can be trained to acquire the necessary delicacy of touch, and can be made to understand that, if they cannot extemporize the necessary polyphony, and so have to play something definitely written for them, it is not a mass of interesting detail which they are to bring to the public ear. A lamentable instance of the prevalent confusion of thought on this point is shown by the vocal scores of the Bach cantatas corresponding to the edition of the Bach Gesellschaft (which must not be held responsible for them). In these Bach’s polyphonic designs are often obliterated beneath a mass of editorial counterpoint (even where Bach has carefully written the words “tasto solo,” i.e. “no filling out”). The same comments apply to the attempts sometimes made to fill out the bare places in 18th-century clavier music. There is no doubt that such filling out was often done on a second harpsichord with stops of a very light tone; but, if it cannot be done on the modern pianoforte in a touch so light as to avoid confusion between it and the notes actually written as essential to the design, it certainly ought not to be done at all. The greater richness of tone of the modern pianoforte is a better compensation for any bareness that may be imputed to pure two-part or three-part writing than a filling out which deprives the listener of the power to follow the essential lines of the music. The same holds good, though in a lesser degree, of the resources of the harpsichord in respect of octave-strings. To sacrifice phrasing, and distinctness in real part-writing, to a crude imitation of the richness produced mechanically on the harpsichord by drawing 4-ft. and 8-ft. registers, is artistically suicidal. The genius of the modern pianoforte is to produce richness by depth and variety of tone; and players who cannot find scope for such genius in the real part-writing of the 18th century will not get any nearer to the 18th-century spirit by sacrificing the essentials of its art to an attempt to imitate its mechanical resources by a modern tour de force.
Symphonic Instrumentation.—The difference between decorative and symphonic instrumentation is admirably shown by Gluck. In the famous dedicatory letter of his Alceste he mentions among other conceptions on which his reform of opera was to be based, that the co-operation of the instruments ought to be regulated in proportion to the interest and the passion, a doctrine of which the true significance lies in its connexion with other conditions of opera which are incompatible with the polyphonic treatment of instruments as threads in a decorative scheme. The date of this famous letter was 1767, but after Alceste Gluck was still able to use material from earlier work; and the overture to Armide is adapted from that of Telemacco, written in the year of Bach’s death (1750).
To write an account of symphonic instrumentation in any detail would be like attempting a history of emotional expression; and all that we can do here is to point out that the problem which was, so to speak, shelved by the polyphonic device of the continuo, was for a long time solved only by methods which, in any hands but those of the greatest masters, were very inartistic conventions. In the new art the concentration of attention upon form, as a more important source of dramatic interest and climax than texture, resulted in a neglect of polyphony which
