The most common and most likely answer to this crossword clue is the 5 letter word HARPS
H
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Buddy explains!

The straight part
We know that "instruments" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case instruments = harps.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 HARPS mean?
HARPS noun- A musical instrument consisting of a body and a curved neck, strung with strings of varying length that are stroked or plucked with the fingers and are vertical to the soundboard when viewed from the end of the body
- A harmonica.
- A grain sieve.
- (usually with on) To repeatedly mention a subject.
- To play on (a harp or similar instrument)
- To play (a tune) on the harp.
- To develop or give expression to by skill and art; to sound forth as from a harp; to hit upon.