Crossword Genius

Harmonics could be obvious ones (9)

Ross

I believe the answer is:

overtones

'harmonics' is the definition.
(overtone is a kind of harmonic)

'obvious ones' is the wordplay.
'obvious' becomes 'overt' ('overt' can be similar in meaning to 'obvious').
'overt'+'ones'='OVERTONES'

'could be' is the link.

(Other definitions for overtones that I've seen before include "Upper partials" , "added nuances" , "subtle innuendoes" , "Subtle implications" .)

I've seen this clue in The Telegraph.
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