Conversation so far:
What instruments were added?
These include the flugelhorn and cornet.
Saxophones and classical guitars, for example, appear in some 19th- through 21st-century scores.
What was the point of adding these?
The 20th-century orchestra was far more flexible than its predecessors.
Did this become common practice?
During the 20th century, the modern orchestra was generally standardized with the modern instrumentation listed below.
What part of the world did this originate?
CANNOTANSWER.
What else did you find interesting about this section?
the orchestra can be analyzed in five periods: the Baroque era, the Classical music period, early/mid-Romantic music era, late-Romantic/early 20th century music and 21st century era.

Question: What details make the orchestras different?
Self-contained rewrite: What details make the orchestras different?