Final answer:
During the "golden age" of wind bands in England, the dramatic change was the enhancement of wind instrument mechanics due to the Industrial Revolution, creating richer sounds and allowing for more complex parts in orchestras.
Step-by-step explanation:
The dramatic change during the "golden age" of the pure wind bands in England was marked by significant developments in musical instruments due to the advancements of the Industrial Revolution. The improvements in mechanical valves and keys of wind instruments led to easier and more reliable playability, as well as a richer and more finely-tuned sound. Instruments that were once auxiliary in orchestras became integral, their parts increasing in complexity and prominence. The evolution of wind bands and the shift toward Romantic music were characterized by the use of more winds in the orchestra, and the refinement of the piano which elevated its status, symbolizing this musical era.