In some scores the music-lover will find the three trombone parts written on three clefs, alto, tenor, and bass, while in others they are written on the bass clef only. I have already noted that bass clarinet parts are written sometimes on the treble and sometimes on the bass clef. The former is always used by French composers, and the latter nearly always by Germans.

PART II

How the Orchestra is Used

VI
General Principles

The orchestra is an instrument, and composers have developed methods of writing for it. The fundamental principles of these methods constitute that branch of musical art called orchestration. It is not the purpose of the present volume to teach that branch; but it is entirely within its province to point out to the reader how composers make use of their majestic and many-voiced instrument. In compass and power alone it surpasses all other instruments. The compass of the modern orchestra is enormous. It extends from grave, low sounds to those of such acute pitch that the ear does not relish them if uttered loudly. The extreme normal compass is shown by the following illustration:

[[audio/mpeg]]

Mr. Corder, in his “Modern Orchestra and How to Write for It,” gives this interesting dynamic scale: “Suppose the degrees of sound-intensity to range from 1 (in ppp) to 12 (in fff); then one might say roughly that

1 2 3 4 5 6 7 8 9 10 11 12
Violins have a range
of fromppp — mp— — —mf — —fff — —
The other stringsppp — —— — —— — fff— — —
Clarinets on high notes— — ppp— — —— fff —— — —
Clarinets low, flutes,
oboes, and bassoons— — ppp— — —fff — —— — —
Horns— ppp —— — —— — fff— — —
Trumpets, trombones,
and drumsppp — —— — —— — —— — fff
Harps— — ppp— — fff— — —— — —

I should modify this by shifting the pianissimo of low clarinet tones back to 2, that of drums forward to 2, and that of trumpets and trombones to 4.