Table A. String group.
(These instruments give all chromatic intervals.)
Black lines on each string denote the general range in orchestral writing, the dotted lines give the registers, low, medium, high, very high.
The five sets of strings with number of players given above produce a fairly even balance of tone. If there is any surplus of strength it must be on the side of the first violins, as they must be heard distinctly on account of the important part they play in the harmonic scheme. Besides this, an extra desk of first violins is usual in all orchestras, and as a general rule they possess a more powerful tone than second violins. The latter, with the violas, play a secondary part, and do not stand out so prominently. The 'cellos and double basses are heard more distinctly, and in the majority of cases form the bass in octaves.
In conclusion it may be said that the group of strings, as a melodic element, is able to perform all manner of passages, rapid and interrupted phrases of every description, diatonic or chromatic in character. Capable of sustaining notes without difficulty, of playing chords of three and four notes; adapted to the infinite variety of shades of expression, and easily divisible into numerous sundry parts, the string group in an orchestra may be considered as an harmonic element particularly rich in resource.
B. Wind instruments.
Wood-wind.
Apart from the varying number of players, the formation of the string group, with its five constituent parts remains constant, satisfying the demands of any orchestral full score. On the other hand the group of wood-wind instruments varies both as regards number of parts and the volume of tone at its command, and here the composer may choose at will. The group may be divided into three general classes: wood-wind instruments in pair's, in three's and in four's, (see table on page 13).
Arabic numerals denote the number of players on each instrument; roman figures, the parts (1st, 2nd etc.). Instruments which do not require additional players, but are taken over by one or the other executant in place of his usual instrument, are enclosed in brackets. As a rule the first flute, first oboe, first clarinet and first bassoon never change instruments; considering the importance of their parts it is not advisable for them to turn from one mouth-piece to another. The parts written for piccolo, bass flute, English horn, small clarinet, bass clarinet and double bassoon are taken by the second and third players in each group, who are more accustomed to using these instruments of a special nature.
| Wood-wind in pair's | Wood-wind in three's | Wood-wind in four's |
| (II—Piccolo). | (III—Piccolo). | 1 Piccolo (IV). |
| 2 Flutes I. II. | 3 Flutes I. II. III. | 3 Flutes I. II. III. |
| (II—Bass flute). | (III—Bass flute). | |
| 2 Oboes I. II. | 2 Oboes I. II. | 3 Oboes I. II. III. |
| (II—Eng. horn). | 1 Eng. horn (III). | 1 Eng. horn (IV). |
| (II—Small clarinet). | (II—Small clarinet). | |
| 2 Clarinets I. II. | 3 Clarinets I. II. III. | 3 Clarinets I. II. III. |
| (II—Bass clarinet). | (III—Bass clarinet). | 1 Bass clarinet (IV). |
| 2 Bassoons I. II. | 2 Bassoons I. II. | 3 Bassoons I. II. III. |
| 1 Double bassoon (III). | 1 Double bassoon (IV). |
The formation of the first class may be altered by the permanent addition of a piccolo part. Sometimes a composer writes for two piccolos or two Eng. horns etc. without increasing the original number of players required (in three's or four's).
Note I. Composers using the first class in the course of a big work (oratorio, opera, symphony, etc.) may introduce special instruments, called extras, for a long or short period of time; each of these instruments involves an extra player not required throughout the entire work. Meyerbeer was fond of doing this, but other composers, Glinka for example, refrain from increasing the number of performers by employing extras (Eng. horn part in Rousslân). Wagner uses all three classes in the above table (in pair's: Tannhäuser—in three's: Tristan—in four's: The Ring).
Note II. Mlada is the only work of mine involving formation by four's. Ivan the Terrible, Sadko, The Legend of Tsar Saltan, The Legend of the Invisible City of Kitesh and The Golden Cockerel all belong to the second class, and in my other works, wood-wind in pair's is used with a varying number of extras. The Christmas Night, with its two oboes, and two bassoons, three flutes and three clarinets, forms an intermediate class.
Considering the instruments it comprises, the string group offers a fair variety of colour, and contrast in compass, but this diversity of range and timbre is subtle and not easily discerned. In the wood-wind department, however, the difference in register and quality of flutes, oboes, clarinets and bassoons is striking to a degree. As a rule, wood-wind instruments are less flexible than strings; they lack the vitality and power, and are less capable of different shade of expression.
In each wind instrument I have defined the scope of greatest expression, that is to say the range in which the instrument is best qualified to achieve the various grades of tone, (forte, piano, cresc., dim., sforzando, morendo, etc.)—the register which admits of the most expressive playing, in the truest sense of the word. Outside this range, a wind instrument is more notable for richness of colour than for expression. I am probably the originator of the term "scope of greatest expression". It does not apply to the piccolo and double bassoon which represent the two extremes of the orchestral compass. They do not possess such a register and belong to the body of highly-coloured but non-expressive instruments.
The four kinds of wind instruments: flutes, oboes, clarinets and bassoons may be generally considered to be of equal power. The same cannot be said of instruments which fulfil a special purpose: piccolo, bass flute, Eng. horn, small clarinet, bass clarinet and double bassoon. Each of these instruments has four registers: low, middle, high and extremely high, each of which is characterised by certain differences of quality and power. It is difficult to define the exact limits of each register; adjacent registers almost blend together and the passage from one to another is scarcely noticeable. But when the instrument jumps from one register to another the difference in power and quality of tone is very striking.
The four families of wind instruments may be divided into two classes: a) instruments of nasal quality and dark resonance—oboes and bassoons (Eng. horn and double bassoon); and b)
