Fan of a fine old company performing song and dance (10)
I believe the answer is:
aficionado
'fan' is the definition.
(I've seen this in another clue)
'a fine old company performing song and dance' is the wordplay.
'fine' becomes 'f' (abbreviation).
'old company' becomes 'ICI' (former company Imperial Chemical Industries).
'performing' becomes 'on' (as in being on stage).
'song and dance' becomes 'ado' (both can mean a commotion or fuss).
'a'+'f'+'ici'+'on'+'ado'='AFICIONADO'
'of' acts as a link.
(Other definitions for aficionado that I've seen before include "Devotee" , "freak" , "Fan; enthusiast" , "supporter" , "Admirer" .)