The most common and most likely answer to this crossword clue is the 9 letter word TROMBONES
I've seen this crossword clue in Independent
T
R
O
M
B
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S
More clues leading to the result TROMBONES
- Brass instruments new to some R’n’B
- Those with the brass to rob men’s pants
- Briefly try old doctor, one with special instruments
- Members of the Royal Ordnance Military Band originally playing note on top of slide
- Instruments of death returned by doctor
- Instruments put steaks in the right order? Just the opposite!
Buddy explains!

The straight part
We know that "Members of the Royal Ordnance Military Band originally playing note on top of slide" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case members of the royal ordnance military band originally playing note on top of slide = trombones.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 TROMBONES mean?
TROMBONES noun- A musical instrument in the brass family, having a cylindrical bore, and usually a sliding tube (but sometimes piston valves, and rarely both). Most often refers to the tenor trombone, which is the most common type of trombone and has a fundamental tone of B♭ˌ (contra B♭).
- The common European bittern.