Answer:
Timpani, the large drums featured in orchestras, originated more than 2000 years ago in ancient empires.
Explanation:
This is one way to add the description after the noun. It's called an "appositive phrase" Timpani=drums So there are two nouns in a row that refer to the same thing.
Another way:
Timpani, which are large drums featured in orchestras, originated more than 2000 years ago in ancient empires.
That's a relative clause. It substitutes the relative pronoun, 'which' for timpani, and keeps the verb, 'are.'
