Demolished villa claimed by star composer (8)
I believe the answer is:
sullivan
'composer' is the definition.
(Sullivan is an example)
'demolished villa claimed by star' is the wordplay.
'demolished' indicates anagramming the letters.
'claimed by' means one lot of letters goes inside another.
'star' becomes 'sun' (Sun is an example).
'villa' with letters rearranged gives 'lliva'.
'lliva' put within 'sun' is 'SULLIVAN'.
(Other definitions for sullivan that I've seen before include "Composer of music for Ruddigore, d. 1900" , "Savoy Opera composer" , "Sir Arthur" , "Mikado composer" , "Gilbert's partner" .)