unison:

[Music]

Enclosure of parts may be used in single chords:

[Music]

or in progression:

[Music]

Three-part writing.

The best combination is trombones, horns, or trumpets in three's. If
the instruments are mixed the number of horns should be doubled:

[Music] etc.

Writing in several parts.

When the whole group is used the number of horns should be doubled:

[Music] etc.

In seven, six, or five-part harmony certain instruments must be
omitted:

[Music]

[Music] etc.

Discords of the seventh or second are preferably entrusted to
instruments of different tone colour:

[Music]

When such chords are written for an orchestra which only includes two
trumpets, it is impossible for the horns to proceed in pairs. In such
cases the following arrangement may obtain, the horns being marked one
degree louder than the other instruments, to secure balance of tone:

[Music]

The same method should be followed whenever the use of horns in pairs
fails to produce satisfactory tone.

When chords of widely-divided harmony are distributed throughout
several harmonic registers, the register occupied by the horns need
not be doubled; the arrangement of the chord will resemble that of a
chorale written for double or triple choir. For example:

[Music]

Duplication in the brass.

Duplication in the brass group is most frequently effected by placing
a chord for horns side by side with the same chord written for
trumpets or trombones. The soft round quality of the horns intensifies
the tone, and moderates the penetrating timbre of the trumpets and
trombones:

[Music]

Similar juxtaposition of trumpets and trombones:

[Music]

is not so common, as this unites the two most powerful agents in the
group.

In handling an orchestra the brass is frequently employed to sustain
notes in two or three octaves; this sphere of activity must not be
ignored. The _tenuto_ is generally given to two trumpets, or to two or
four horns in the octave, (in double octaves). The octave is sometimes
formed by trumpets and horns acting together:

[Music]

The trombone with its ponderous tone rarely takes part in such
combinations. Sustained notes in double octaves are usually
apportioned thus:

[Music]

The imperfect balance arising from the duplication of the middle note
is compensated for by the mixture of timbres, which lends some unity
to the chord.

_Examples of harmony in the brass:_

a) Independent cho