dled, will sound equally
well if played by strings, wood-wind or brass.

The composer should picture to himself the exact harmonic formation of
the piece he intends to orchestrate. If, in his rough sketch, there
exist any uncertainly as to the number or movement of harmonic parts,
he is advised to settle this at once. It is likewise essential for him
to form a clear idea as to the construction and musical elements of
the piece, and to realise the exact nature and limitations of the
themes, phrases and ideas he is going to employ. Every transition from
one order of harmonic writing to another, from four-part harmony to
three, or from five-part harmony to unison etc., must coincide with
the introduction of a new idea, a fresh theme or phrase; otherwise the
orchestrator will encounter many unforeseen and insurmountable
difficulties. For example, if, during a passage written in four parts
a chord in five-part harmony is introduced, a fresh instrument must
needs be added to play this particular fifth part, and this addition
may easily damage the resonance of the chord in question, and render
the resolution of a discord or the correct progression of parts
impossible.

Number of harmonic parts--Duplication.

In the very large majority of cases harmony is written in four parts;
this applies not only to single chords or a succession of them, but
also to the formation of the harmonic basis. Harmony which at first
sight appears to comprise 5, 6, 7 and 8 parts, is usually only four
part harmony with extra parts added. These additions are nothing more
than the duplication in the adjacent upper octave of one or more of
the three upper parts forming the original harmony, the bass being
doubled in the lower octave only. The following diagrams will explain
my meaning:

[Music: _A. Close part-writing._

Four part harmony.
Duplication of 1 part.
Duplication of 2 parts.
Duplication of 3 parts.]

[Music: _B. Widely-divided part-writing._

Four part harmony.
Duplication of 1 part.
Duplication of 2 parts.]

_Note._ In widely-spaced harmony only the soprano and alto
parts may be doubled in octaves. Duplicating the tenor part
is to be avoided, as close writing is thereby produced, and
doubling the bass part creates an effect of heaviness. The
bass part should never mix with the others:

Bad: [Music]

On account of the distance between the bass and the three other parts,
only partial duplica