Final answer:
The size of orchestras in the nineteenth century did not decrease; instead, orchestras expanded during this period. Advancements in instrument design and the rise of middle-class audiences, who attended public concerts, supported larger and more dynamic orchestras, contrary to option b. The woodwind, brass, and percussion sections all saw significant enhancements and additions.
Step-by-step explanation:
Of the options provided, the one that does not describe orchestras of the nineteenth century is b. The size of the orchestras decreased, using more compact ensembles.
On the contrary, the nineteenth century saw the expansion of orchestra sizes and their dynamics. This period is marked by substantial changes in the composition and range of orchestras. The Industrial Revolution brought about advancements in instrument design, allowing new instruments to be added to woodwind and brass sections, and making them more reliable and sonorous. Composers began to explore the full range of these instruments, producing more complex and impactful music.
Furthermore, the rise of the middle class influenced music by expanding the audience and leading to public concerts with large audiences who patronized performances, thus supporting the trend of larger orchestras. Romantic composers, who were often writing for large public concerts, substantially contributed to the dynamic range and size of orchestras.
Lastly, the percussion section also saw expansion during this era. With the invention of new percussion instruments and the inclusion of existing ones into symphonic music, the role and complexity of the percussion section grew significantly.