Chapter I.
GENERAL REVIEW OF ORCHESTRAL GROUPS.
A. Stringed Instruments.
The following is the formation of the string quartet and the number of players required in present day orchestras, either in the theatre or concert-room.
| Full orchestra | Medium orchestra | Small orchestra | |
| Violins I | 16 | 12 | 8 |
| " II | 14 | 10 | 6 |
| Violas | 12 | 8 | 4 |
| Violoncellos | 10 | 6 | 3 |
| Double basses | 8-10 | 4-6 | 2-3 |
In larger orchestras, the number of first violins may amount to 20 and even 24, the other strings being increased proportionately. But such a great quantity of strings overpowers the customary wood-wind section, and entails re-inforcing the latter. Sometimes orchestras contain less than 8 first violins; this is a mistake, as the balance between strings and wind is completely destroyed. In writing for the orchestra it is advisable to rely on a medium-sized body of strings. Played by a larger orchestra a work will be heard to greater advantage; played by a smaller one, the harm done will be minimised.
Whenever a group of strings is written for more than five parts—without taking double notes or chords into consideration—these parts may be increased by dividing each one into two, three and four sections, or even more (divisi). Generally, one or more of the principal parts is split up, the first or second violins, violas or violoncellos. The players are then divided by desks, numbers 1, 3, 5 etc. playing the upper part, and 2, 4, 6 etc., the lower; or else the musician on the right-hand of each desk plays the top line, the one on the left the bottom line. Dividing by threes is less easy, as the number of players in one group is not always divisible by three, and hence the difficulty of obtaining proper balance. Nevertheless there are cases where the composer should not hesitate to employ this method of dividing the strings, leaving it to the conductor to ensure equality of tone. It is always as well to mark how the passage is to be divided in the score; Vns I, 1, 2, 3 desks, 6 'Cellos div. à 3, and so on. Division into four and more parts is rare, but may be used in piano passages, as it greatly reduces volume of tone in the group of strings.