The most common and most likely answer to this crossword clue is the 6 letter word TIMBRE
I've seen this crossword clue in The Guardian
T
I
M
B
R
E
More clues leading to the result TIMBRE
- Sound quality of wood finally being turned
- Sound quality of Britain reduced in time
- What Archer did about British quality
- Without hesitation, Brummie recklessly pursues model quality
- Tone with which doctor plugs drain
- Quality of wood that is a bit twisted at one end
- Rice gets British capital for Evita — or The Sound of Music
- Quality of magazine about Britain
- Doctor engaged in weary tone
- Weary about doctor’s tone
Buddy explains!

The straight part
We know that "Tone" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tone = timbre.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 TIMBRE mean?
TIMBRE noun- The quality of a sound independent of its pitch and volume.
- The pitch of a sound as heard by the ear, described relative to its absolute pitch.
- The crest on a coat of arms.