Final answer:
Beethoven incorporated new instruments such as the piccolo, trombones, and contrabassoon in his symphonies, particularly in his Ninth Symphony where he also included voices, contributing significantly to the evolution of orchestral music from the Classical to the Romantic era.
Step-by-step explanation:
Ludwig van Beethoven, a pivotal composer in classical music history, expanded the orchestral palette by incorporating new instruments into his compositions. During the transition from the Classical to the Romantic era, technological advancements significantly improved many instruments, particularly brass and woodwinds, enabling composers to explore new sonic possibilities.
Beethoven's innovative use of the orchestra can be heard in his Symphony No. 5 where he added the piccolo, trombones, and contrabassoon to enrich the orchestral texture. His most notable expansion occurred in the Ninth Symphony, where he included parts for the piccolo, trombones, and notably added voices to the final movement, thereby creating a choral symphony.
These additions allowed for a fuller sound and more complex musical structures that have influenced countless composers after him.