The most common and most likely answer to this crossword clue is the 7 letter word CLAVIER
I've seen this crossword clue in Independent
C
L
A
V
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More clues leading to the result CLAVIER
- Instrument’s a relic, unfortunately possessing little volume
- In Clare never ending contest for musical instrument
- Keyboard instrument‘s existence at Versailles, in possession of Councillor
- Caught old tennis star pocketing one keyboard
- Keyboard instrument from first of concerts I ravel carefully
- To start computer, laptop and various IT equipment requires a keyboard
- Keyboard‘s overspecialised in design — troublesome episodes eliminated
Buddy explains!

The straight part
We know that "musical instrument" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case musical instrument = clavier.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 CLAVIER mean?
CLAVIER noun- The keyboard of an organ, pianoforte, or harmonium.