Revolutionary 'Something in the Air', with a narrative (4)
I believe the answer is:
saga
'narrative' is the definition.
(I've seen this before)
'revolutionary something in the air with a' is the wordplay.
'revolutionary' shows that the letters should be reversed in order.
'something in the air' becomes 'gas' (eg oxygen, nitrogen etc).
'with' is a charade indicator (letters next to each other).
'gas' backwards is 'sag'.
'sag'+'a'='SAGA'
(Other definitions for saga that I've seen before include "Body of legend" , "Chronicle; adventure" , "Norse epic" , "Icelandic or Norse story" , "Norse narrative" .)