The most common and most likely answer to this crossword clue is the 7 letter word SINGERS
I've seen this crossword clue in Financial Times
S
I
N
G
E
R
S
Buddy explains!

The straight part
We know that "Chorus" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case chorus = singers.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SINGERS mean?
SINGERS noun- A person who sings, often professionally.
- (square dance) dance figure with a fixed structure, sung by a caller, or a piece of music with that structure.
- A person who, or device which, singes.
- A machine for singeing cloth.
- A person who sings, often professionally.
- (square dance) dance figure with a fixed structure, sung by a caller, or a piece of music with that structure.
- A person who, or device which, singes.
- A machine for singeing cloth.