Problems With Nouns (2): Singular Expressions of Non-count Nouns.

(A folk song is [a] [piece] [of] [popular music])

- A folk song is
- (a): a
- (singular): piece
- (of)
- (noun[non-count]): popular music

Remember that the following singular expressions are idiomatic:

- a piece of bread
- a piece of equipment
- a piece of furniture
- a piece of jewelry
- a piece of luggage
- a piece of mail
- a piece of music
- a piece of toast
- a loaf of bread
- a slice of bread
- an ear of corn

Incorrect: (A mail) travels faster when the zip code is indicated on the envelope.
Correct: (A piece of mail) travels faster when the zip code is indicated on the envelope.

Incorrect: There is a limit of (one carry-on luggage) for each passenger.
Correct: There is a limit of (one piece of carry-on luggage) for each passenger.

Incorrect: (Each furniture) in this display is on sale for half price.
Correct: (Each piece of furniture) in this display is on sale for half price.

Incorrect: I'd like a steak, a salad, and (a corn's ear) with butter.
correct: I'd like a steak, a salad, and (an ear of corn) with butter.

Incorrect: The Engineering Department purchased (a new equipment) to simulate conditions in outer space.
Correct: The Engineering Department purchased (a new piece of equipment) to simulate conditions in outer space.