The very nature of the stylized idiomatic characteristics of the brass section as orchestral instruments precludes any systematic application of the Reference Chart of Keyboard Idioms and Patterns as carried out for the strings and woodwinds. However, certain entries of the Reference Chart have been examined in the surveys for each instrument. Others will be discussed in the chapters devoted to scoring for full orchestra.
In planning orchestrations it is helpful to divide the brass section into two units: (1) the horns, and (2) the trumpets, trombones, and tuba. This division is pertinent because of the great diverse tonal strengths and weights between these units, which affect scoring plans. The superior blending qualities of the horns has occasioned some musicologists to associate them with the wood-winds rather than with the brass section. The remaining heavier brasses have the strongest timbres and should therefore be reserved for passages requiring extra power, sonority, and intensity.
The spectacular emergence of the brass section to a position of unprecedented dominance in the past century should be viewed in the context of changing trends in composition. These trends have led to an ever-increasing emphasis on tonal brilliance and volume through expanded contrapuntal textures and harmonic vocabularies. Nonetheless, a survey of orchestral scores from the early Classic period through the twentieth century will reveal that the sensitive orchestrator has respected orchestral values by differentiating between the appropriate and the in-appropriate. To cite but one example: Ravel's scoring of his suite Ma Mere Voye is entirely different from that for his choreographic poem La Valse. A perusal of the instrumentation for both works discloses their points of departure and intended scope.
The listing which follows summarizes the most common phases of scoring for the brass instruments either as an independent unit or in combination with the strings and wood-winds. The ten points should be integrated with the analysis given for each instrument so that they can become part of a practical scoring technique. They are closely allied to corresponding entries in the Reference Chart of Keyboard Idioms and Patterns.
1. Solo and octave melodic lines at all dynamic levels
2. Chordal progressions in choral style
3. Unisons, intervals, and chords used for percussive accents
4. Sustaining single notes, intervals, and chords at all dynamic levels
5. Rhythmic figurations
6. Outlining important melodies
7. Doubling strings and/or wood-winds in unison or octaves for extra emphasis and tonal strength
8. Increasing sonority for climaxes
9. As an independent section for contrasts in timbre and sonority
10. Coloristic effects
Representative excerpts for the brass section as an independent unit are given in Example B-34. They illustrate the section's aptness for chordal progressions horizontally conceived.