Final answer:
The piano, invented by Bartolomeo Cristofori around 1700, emerged during the Classical Period and allowed for greater dynamic expression in music, eventually becoming a symbol of Romantic music.
Step-by-step explanation:
One new musical instrument that emerged during the Classical Period was the pianoforte, commonly known as the piano. It was invented by Bartolomeo Cristofori around the year 1700. The piano started to usurp the position of the harpsichord during the second half of the eighteenth century and is considered a symbol of Romantic music. Unlike the harpsichord, which plucks strings, the piano strikes strings with hammers, allowing for greater dynamic expression. This capacity for dynamic range and expression was a defining characteristic of the Classical music era, exemplified by the work of composers like Mozart and Haydn.