Ventilate a tune (3)

I believe the answer is:

air

I believe this clue is a double definition.

'ventilate' is the first definition.
(synonyms)

'a tune' is the second definition.
('air' can be a synonym of 'tune')

(Other definitions for air that I've seen before include "Ventilate or give expression to" , "Atmosphere; appearance" , "Gas mixture required for breathing" , "Bearing, manner" , "Simple tune" .)

I've seen this clue in the Sydney Morning Herald.

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