The most common and most likely answer to this crossword clue is the 5 letter word TROOP
I've seen this crossword clue in The Times
T
R
O
O
P
More clues leading to the result TROOP
- Weak trombone initially repelled a musical group perhaps
- Bad time to bring back group of soldiers
- Group of soldiers left upset about nothing
- March — miserable time for uprising
- Run into very quiet group of soldiers
- Fighting unit of soldiers retreating into cover?
- Soldiers knocked back drink? Nothing to be admitted
- Soldiers having miserable time in retreat
- Men replaced in best part of a squadron
- Violent end met by destitute retreating soldiers
Buddy explains!

The straight part
We know that "musical group" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case musical group = troop.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 TROOP mean?
TROOP noun- (collective) A collection of people; a number; a multitude (in general).
- A small unit of cavalry or armour commanded by a captain, corresponding to a platoon or company of infantry.
- A detachment of soldiers or police, especially horse artillery, armour, or state troopers.
- Soldiers, military forces (usually "troops").
- A company of stageplayers; a troupe.
- A basic unit of girl or boy scouts, consisting of 6 to 10 youngsters.
- (collective) A group of baboons.
- A particular roll of the drum; a quick march.
- Mushrooms that are in a close group but not close enough to be called a cluster.
- To move in numbers; to come or gather in crowds or troops.
- To march on; to go forward in haste.
- To move or march as if in a crowd.