Very calm about publicity for love song (8)
I believe the answer is:
serenade
'love song' is the definition.
(a serenade might be sung to a lover)
'very calm about publicity' is the wordplay.
'very calm' becomes 'serene' (I've seen this in another clue).
'about' indicates putting letters inside.
'publicity' becomes 'ad' (short for advert).
'serene' going around 'ad' is 'SERENADE'.
'for' acts as a link.
(Other definitions for serenade that I've seen before include "Song to a lover" , "Evening love song" , "Noted performance" , "Song of romance" , "Sing (for someone on a balcony?)" .)