The most common and most likely answer to this crossword clue is the 9 letter word PROKOFIEV
I've seen this crossword clue in The Times
P
R
O
K
O
F
I
E
V
More clues leading to the result PROKOFIEV
- Evidence I’ve altered implicating King’s Head music man
- Sanction framed by academic that is against composer
- He scored for City by cutting inside
- Evidence I’ve translated about Köchel for composer
- Musician’s press release to approve disc by Furious Five
- Composer of “Viper” OK after injury
- Musician's press release to approve disc by Furious Five
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 = prokofiev.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.