Percussion instruments producing indefinite sounds.
Instruments in this group, such as triangle, castanets, little bells, tambourine, switch or rod (Rute. Ger.), side or military drum, cymbals, bass drum, and Chinese gong do not take any harmonic or melodic part in the orchestra, and can only be considered as ornamental instruments pure and simple. They have no intrinsic musical meaning, and are just mentioned by the way. The first three may be considered as high, the four following as medium, and the last two as deep instruments. This may serve as a guide to their use with percussion instruments of determinate sounds, playing in corresponding registers.
Comparison of resonance in orchestral groups and
combination of different tone qualities.
In comparing the resonance of the respective groups of sound-sustaining instruments we arrive at the following approximate conclusions:
In the most resonant group, the brass, the strongest instruments are the trumpets, trombones and tuba. In loud passages the horns are only one-half as strong, 1 Trumpet = 1 Trombone = 1 Tuba = 2 Horns. Wood-wind instruments, in forte passages, are twice as weak as the horns, 1 Horn = 2 Clarinets = 2 Oboes = 2 Flutes = 2 Bassoons; but, in piano passages, all wind-instruments, wood or brass are of fairly equal balance.
It is more difficult to establish a comparison in resonance between wood-wind and strings, as everything depends on the number of the latter, but, in an orchestra of medium formation, it may be taken for granted that in piano passages, the whole of one department (all 1st Violins or all 2nd Violins etc.) is equivalent in strength to one wind instrument, (Violins I = 1 Flute etc.), and, in forte passages, to two wind instruments, (Violins I = 2 Flutes = 1 Oboe + 1 Clarinet, etc.).
It is still harder to form a comparison with instruments of little sustaining power, for too great a diversity in production and emission of sound exists. The combined force of groups of sustained resonance easily overpowers the strings played pizz. or col legno, the piano played softly, or the celesta. As regards the glockenspiel, bells, and xylophone, their emphatic tone will easily prevail over other groups in combination. The same may be said of the kettle-drums with their ringing, resounding quality, and also of other subsidiary instruments.
The influence of the timbre of one group on another is noticeable when the groups are doubled; for instance, when the wood-wind timbre is closely allied to the strings on the one hand, and to the brass on the other. Re-inforcing both, the wind thickens the strings and softens the brass. The strings do not blend so well with the brass, and when the two groups are placed side by side, each is heard too distinctly. The combination of the three different timbres in unison produces a rich, mellow and coherent tone.
All, or several wind instruments in combination will absorb one department of added strings:
| 2 Fl. | + | 2 Ob. | + | Vns I, | |
| or: | 2 Ob. | + | 2 Cl. | + | Violas, |
| or: | 2 Cl. | + | 2 Fag. | + | 'Cellos. |
One department of strings added to the wood-wind in unison produces a sweet coherent quality, the wood-wind timbre still predominating; but the addition of one wind instrument to all or part of the strings in unison, only thickens the resonance of the latter, the wood-wind timbre being lost in the process:
| Vns I | + | Vns II | + | 1 Ob., | |
| or: | Violas | + | 'Cellos | + | 1 Cl. |
| or: | 'Cellos | + | D. basses | + | 1 Fag. |
Muted strings do not combine so well with wood-wind, as the two tone qualities remain distinct and separate. Uniting plucked strings and percussion with instruments of sustained resonance results in the following: wind instruments, wood and brass, strengthen and clarify pizzicato strings, harp, kettle-drums and percussion generally, the latter lending a touch of relief to the tone of the wood-wind. Uniting plucked strings and percussion with bowed instruments does not produce such a satisfactory blend, both qualities being heard independently. The combination of plucked strings with percussion alone, is excellent; the two blend perfectly, and the consequent increase in resonance yields an admirable effect.
The relationship which exists between string harmonics and the flute or piccolo constitutes a link between the two groups in the upper range of the orchestra. Moreover, the timbre of the viola may be vaguely compared to the middle register of the bassoon and the lowest compass of the clarinet; hence, in the medium orchestral range, a point of contact is established between the quartet of strings and the wood-wind.
The bassoon and horn provide the connection between wood-wind and brass, these two instruments being somewhat analogous in character when played piano or mezzo-forte; the flute also, in its lowest register, recalls the pianissimo trumpet tone. Stopped and muted notes in horns and trumpets are similar in quality to the oboe and Eng. horn, and blend tolerably well with the latter instrument.
Concluding this survey of orchestral groups I add a few remarks which seem to me of special importance.
The principal part in music is undertaken by three instrumental groups of sustained resonance, representing the three primary elements, melody, harmony and rhythm. Instruments of little sustaining power, though sometimes used independently, are chiefly employed for ornament and colour; instruments producing indeterminate sounds play no melodic or harmonic part, their functions being purely rhythmical.
By glancing at the order in which the six orchestral groups are placed, strings, wood-wind, brass, plucked strings, percussion producing definite, and those producing indefinite sounds, the reader will be able to determine the part played by each in the art of orchestration, from the secondary standpoint of colour and expression. As regards expression, the strings come first, and the expressive capacity of the other groups diminishes in the above order, colour being the only attribute of the last group of percussion instruments.
The same order obtains from the standpoint of general effect in orchestration. We can listen to strings for an almost indefinite period of time without getting tired, so varied are their characteristics (vide the number of string quartets, suites, serenades etc. written for strings alone). The addition of a single group of strings will add lustre to a passage for wind instruments. On the other hand, the quality of wind instruments soon becomes wearisome; the same may be said of plucked strings, and also percussion of every kind which should only be employed at reasonable intervals in orchestral composition.
It cannot be denied that the constant use of compound timbres, in pair's, in three's etc. eliminates characteristics of tone, and produces a dull, neutral texture, whereas the employment of simple, elementary combinations gives infinitely greater scope for variety in colour.
7 (20) June 1908.
Chapter II.
MELODY.
Whether it be long or short, a simple theme or a melodic phrase, melody should always stand out in relief from the accompaniment. This may be done by artificial or natural means; artificially, when the question of tone quality does not come into consideration, and the melody is detached by means of strongly accentuated dynamic shades; naturally, by selection and contrast of timbres, strengthening of resonance by doubling, tripling, etc., or crossing of parts (violoncellos above the violas and violins, clarinets or oboes above the flutes, bassoons above the clarinets etc.).
Melody planned in the upper parts stands out from the very fact of position alone, and likewise, to a less degree when it is situated in the low register. In the middle of the orchestral range it is not so prominent and the methods referred to above come into operation. They may also be employed for two part melody (in thirds and sixths) and for polyphonic writing.