Definition
A doubling is the same line given to two or more instruments, in unison or at the octave. A blend is the timbre that results from the combination. Orchestration is largely the art of choosing doublings: with the same chords and the same melody you can obtain opposite colors. Reference texts: Rimsky-Korsakov (Principles of Orchestration), Adler (The Study of Orchestration), Piston (Orchestration).
Unison and octave
- Unison of identical timbres (16 violins): a richer sound but not proportionally louder (the volume grows by a few dB, the timbre “widens”).
- Unison of different timbres: a new timbre is born. Flute + violin = a sweeter violin; oboe + violin = a more nasal, penetrating violin; clarinet + viola = dark and warm.
- Octave: clarifies and widens the line without changing the basic timbre. Violins I with flute an octave above: a luminous melody. Cellos with basses an octave below: a solid bass.
- Double or triple octave: everyone in unison in octaves for a powerful theme (end of the tuttis).
Classic doublings by register
- High melody: Vl I + fl (8va) + ob (unison) for a forte; Vl I + fl (unison) for a piano.
- Tenor-range melody: Vc + bsn + horn (unison): warm and noble.
- Low melody: Vc + Cb + bsn + tuba (octaves) for drama.
- Chorale: horns + bassoons + clarinets: a soft blend.
- Sparkle: celesta + glockenspiel + harp + violins in pizzicato.
The horn as “glue”
The horn blends with the woodwinds, the brass, and the strings alike. A sustained horn note under a string passage ties the sections together without being noticed. Many orchestrators use it as a harmonic pedal in the middle register.
Chord-overlapping techniques (woodwinds and mixed)
According to Adler:
- Juxtaposition: each pair of instruments in a register (flutes on top, oboes below, clarinets lower still).
- Interlocking: fl1, ob1, fl2, ob2 alternating: a more homogeneous blend.
- Enclosure: one timbre inside another (oboes between the two flutes).
- Overlapping: two timbres that double some notes in common.
Balance
At a forte, one trombone or one trumpet balances about two horns; one horn about two woodwinds. Strings in a section are more numerous and hold their own against winds in pairs. A melody in the middle-low register of the woodwinds is covered by strings and brass: it must be doubled or left uncovered.
Imitating harmonics: Ravel's Boléro
In Boléro (1928) Ravel gives the melody to horn and celesta, with two piccolos playing the same melody at intervals of a twelfth and a seventeenth (in different keys): the parallel lines imitate harmonics and fuse into an “organ-like” timbre. It is the most frequently cited example of doubling not at the octave.
Doublings in pop production
The same principles apply to layers: a piano + a pad in unison; a synth lead + a guitar an octave below; lead vocal + a whispered double an octave below (see Vocal Stacks). The rule: a doubling must have a reason (more weight, more brilliance, more warmth), not just “more sound.”
Common mistakes
- Doubling everything: the orchestra loses color and turns gray.
- Unison doublings of instruments tuned differently (in the virtual world: two different libraries with slightly different tuning produce beating).
- Doubling the melody with the wrong instrument for the register (low flute under high violins: inaudible).
Practical exercise
Write an 8-bar melody in G major. Orchestrate it in three versions: intimate (fl + vl I in unison, muted strings), noble (vc + horn + bsn in unison), triumphant (vl I + ob + trumpet, with fl and piccolo an octave above, brass and timpani). Listen to how the same line changes meaning.
Related topics
Orchestration: Families, Ranges, and Blends, Strings, Woodwinds, Brass, Percussion, Layering and Arranging by Frequency and Stereo.