The most common and most likely answer to this crossword clue is the 7 letter word BERLIOZ
I've seen this crossword clue in Financial Times
B
E
R
L
I
O
Z
More clues leading to the result BERLIOZ
- Frenchman behind bars, Republican held by priest in Dickens
- Man of note scarcely heard down under
- Composer’s never-ending capital in Germany and Australia
- French composer attaching little weight to Brel after change of heart
- Member divided just over three pounds, maybe for barman
- British Queen Elizabeth admitting love for French musician
- Dickens claims wizard discovered composer
- Boiler fixed by unknown bloke once offering staff work?
Buddy explains!
The straight part
We know that "French composer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case french composer = berlioz.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.