Final answer:
When the tonality changes and only strings and woodwinds play, it is a common orchestral technique used to create a different sound and atmosphere. Strings and woodwind instruments play a significant role in this type of orchestration, allowing composers to evoke different emotions and moods in their compositions.
Step-by-step explanation:
When the tonality changes and only strings and woodwinds play, it is a common technique used in orchestral music to create a different sound and atmosphere. The tonality refers to the overall harmonic characteristics of a piece of music. When the tonality changes, it means that the key or mode of the music shifts, resulting in a different set of pitches and chords being used.
Strings and woodwind instruments play a significant role in this type of orchestration. Strings, like the violin and cello, produce sound through vibrated strings, while woodwinds, like the clarinet and flute, produce sound through vibrating reeds or blowing across a mouthpiece. These instruments can create a wide range of timbres and dynamics, allowing composers to evoke different emotions and moods in their compositions.
For example, when a piece transitions from a bright and lively major key to a dark and mysterious minor key, the composer may choose to emphasize the strings and woodwinds to enhance the change in tonality and convey a sense of tension or melancholy.