Song composed about the present time (8)
I believe the answer is:
serenade
'song' is the definition.
(I know that serenade is a type of song)
'composed about the present time' is the wordplay.
'composed' becomes 'serene' (I've seen this in other clues).
'about' means one lot of letters goes inside another.
'the present time' becomes 'AD' (AD, Anno Domini, as opposed to BC, Before Christ).
'serene' enclosing 'ad' is 'SERENADE'.
(Other definitions for serenade that I've seen before include "Song to a lover" , "It's played or sung at a lover's window" , "Noted performance" , "Piece sung beneath beloved's window" , "Piece of music for lovers at night" .)