Utter in a semitone (4)

I believe the answer is:

emit

'utter' is the definition.
(I know that utter can be written as emit)

'in a semitone' is the wordplay.
'in' says the answer is hidden in the clue.
'EMIT' can be found hidden inside 'semitone'.

(Other definitions for emit that I've seen before include "Sent" , "Give out (eg light)" , "'Give out, light say (4)'" , "Give off, gas say" , "Discharge - utter" .)

I've seen this clue in the Evening Standard.

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