The most common and most likely answer to this crossword clue is the 5 letter word CODAS
I've seen this crossword clue in The Times
C
O
D
A
S
Buddy explains!
The straight part
We know that "closing bars" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case closing bars = codas.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 CODAS mean?
CODAS noun- A person born hearing to deaf parents.
- A passage that brings a movement or piece to a conclusion through prolongation.
- The optional final part of a syllable, placed after its nucleus, and usually composed of one or more consonants.
- In seismograms, the gradual return to baseline after a seismic event. The length of the coda can be used to estimate event magnitude, and the shape sometimes reveals details of subsurface structures.
- A conclusion (of a statement or event, for example), final portion, tail end.