The most common and most likely answer to this crossword clue is the 5 letter word HOLST
I've seen this crossword clue in The Guardian
H
O
L
S
T
More clues leading to the result HOLST
- Composer’s unfortunate sloth
- Entertainer bringing in latest from musical composer
- Composer’s vacation close to forest
- Composer shortening vacation time
- Landlord accommodates student composer
- Hearts lost injured scorer
- Break back of net, as scorer
- He produced astronomic score in first of tests after break
- He scored, left mobbed by crowd
- Composer has temperature following short vacation
Buddy explains!

The straight part
We know that "composer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case composer = holst.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.