Arrange a site for composer (5)
I believe the answer is:
satie
'for composer' is the definition.
(French composer Erik Satie)
'arrange a site' is the wordplay.
'arrange' is an anagram indicator.
'a'+'site'='asite'
'asite' with letters rearranged gives 'SATIE'.
(Other definitions for satie that I've seen before include "Erik -----, French early minimalist composer" , "creative Frenchman" , "scorer" , "French composer (Trois Gymnopedies)" , "French composer of the Gymnopedies, d. 1925" .)