The previous chapter dealt with some important but relatively unsubtle color changes. Here, we hone in on some of the finer methods for making detailed changes of this kind, organizing the chapter around the apparent motivations for these changes, seeking to create:

a timbral cadence

a smooth structural boundary;

an "attack-sustain" ("resonance") effect

a seamless orchestral crescendo

a timbrally nuanced melody

For a timbral cadence

Apart from changing the timbral distribution between sections (after a cadence), some composers make changes for the cadence itself, emphasizing the cadential moment. This is related to the more formal considerations of holding back a timbre discussed in the previous chapter.

Classical-era orchestral composers sometimes used wind parts in this way. Here’s an example from the opening of Mozart’s Piano Concerto K453, movement 3. The strings begin, and the timbral cadences are marked by the addition of winds (highlighted in the example).

Mozart K453

Shostakovich provides some extraordinary 20th-century examples of this device. Consider the end of Shostakovich 11/iii. The outer sections of this movement are effectively one long viola solo, and the timbral addition of unison violins at the end is integral to formalizing the end of the theme. The melodic contour and discontinuation of the countersubject are also contributing, but the harmony is deeply ambiguous. In the following recording, the theme plays from 0’50” and the timbral cadences fall at the ends of the sections (4’50” and 12’40”).

https://open.spotify.com/track/75N4wFxecJ1tPdy4Jvc2d1?si=_5kv3h_YTT2egr3f3OHcxQ

This device is not unique to orchestral music. For instance, Blink 182 uses the same effect to close verses in the song "I Miss You": here the timbral cadence is achieved by the addition of the other vocalist (e.g., at 0'55").

To finesse a structural boundary

Timbral additions can also be used in the opposite sense: to finesse a structural boundary and actively connect the two sections. This is a favored device of Brahms. Brahms 2/iii opens with a gracious oboe theme, and it is the return of the oboe (in tandem with motivic handling and other matters) that finesses the return to the A section at m. 101/107.

Brahms 2 iii

It is the oboe again that Brahms adds to round out the first cadence of Brahms 4/i. (Note also the cello-viola dovetailing here.)

Brahms 4 i

For the "attack-sustain" ("resonance") effect

One technique beloved of 20th-century composers is the "attack-sustain" or "resonance" effect. Acoustics teaches us that the very start of a note has a very different profile from the rest, and composers seem to be striving for something similar in orchestral writing that casts some instruments in an "attacking" role (shorter notes at the start) and others as "sustain" (longer notes starting together on the same pitches).

Examples abound and are not limited to the 20th century. For instance:

Mozart: Magic Flute overture. When the brass parts enter, the horns are long, while the trumpets and trombones are short.

Mozart: Dies Irae (from the Requiem): again, trumpets and drums are short; others long.

Beethoven: The opening of Symphony 1/i) is an iconic example, and not only for the extraordinary harmonies. The winds’ fp chords achieve the attack-sustain pair on their own, and are enhanced by string pizzicato (attack only).

In the 20th century, Schoenberg’s groundbreaking "Farben" (no. 3 from Five Orchestral Pieces) includes this effect (e.g., see the harp at reh. 2), and Britten uses it to magnificent effect in movement iii of the Four Sea Interludes. Play the following example from c. 0’45”.

https://open.spotify.com/track/6DEBxm5XrqUfvkqH1Pc3OR?si=Gy9UQTwUShaFIqwXRVq0EQ

Britten uses penetrating instruments for the attacks (including the harp again) and sets the resonance on sustained flute lines, as shown in this small excerpt:

"Attack-sustain" detail from Britten's Four Sea Interludes

(Note the octave transposition of the harp harmonics.) Later in the movement (around reh. 3), the same device appears with xylophone and piccolo on attack, and trumpet sustaining.

This practice is related to the wider device of employing different articulations on doublings of the same melodic line. Clear examples include:

Debussy: La Mer / iii (fig. 55). The oboe has repeated notes; the flute does not.

Sibelius: En Saga: m. 189, (viola pizz. + arco); m. 290 (trumpet staccato with oboe legato), then oboe with viola.

This, in turn, is related to the practice of having string parts play melodies tremolo for loud sections as seen in the Grieg example from the previous chapter.

For a seamless orchestral crescendo

That Grieg example displayed the kind of step-by-step orchestral crescendo that some composers turned into an extremely subtle process. Consider the following example of two extracts from Wagner’s Parsifal. The melody is in unison, and in both cases, a timbre is added at the top of the crescendo. In both cases, a higher, brighter version of an instrument already in the mix is added. In the second case, this is partly for registral reasons (the oboe replaces the bassoon in a high register); in both cases it transforms the sound, very subtly adding a timbral dimension to mark the moment in question.

Wagner - Parsifal extracts

Once again, it falls to the 20th century to furnish us with the truly iconic example of this process. Listen to this short