Still holding an old penny piece (8)
I believe the answer is:
serenade
'piece' is the definition.
(I know that Serenade is a type of piece)
'still holding an old penny' is the wordplay.
'still' becomes 'serene' (I've seen this in another clue).
'holding' is an insertion indicator.
'an' becomes 'a'.
'old penny' becomes 'd' (pre-decimal abbreviation for penny).
'a'+'d'='ad'
'serene' placed around 'ad' is 'SERENADE'.
(Other definitions for serenade that I've seen before include "Musical performance, under a lady's window?" , "Piece of music for courtship" , "Lover's song" , "Piece sung beneath beloved's window" , "Sing (for someone on a balcony?)" .)