The most common and most likely answer to this crossword clue is the 5 letter word TABLA
T
A
B
L
A
Buddy explains!

The straight part
We know that "Percussion instrument" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case percussion instrument = tabla.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 TABLA mean?
TABLA noun- A pair of tuned hand drums, used in various musical genres of the Indian subcontinent, that are similar to bongos.