The most common and most likely answer to this crossword clue is the 10 letter word ORCHESTRAS
I've seen this crossword clue in The Daily Telegraph
O
R
C
H
E
S
T
R
A
S
More clues leading to the result ORCHESTRAS
Buddy explains!

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 ORCHESTRAS mean?
ORCHESTRAS noun- A large group of musicians who play together on various instruments, usually including some from strings, woodwind, brass and/or percussion; the instruments played by such a group.
- A semicircular space in front of the stage used by the chorus in Ancient Greek and Hellenistic theatres.
- The area in a theatre or concert hall where the musicians sit, immediately in front of and below the stage, sometimes (also) used by other performers.