"Surprise Symphony" composer (5)
I believe the answer is:
haydn
'surprise symphony composer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for haydn that I've seen before include "The Surprise symphony composer, d. 1809" , "Barman" , "Austrian symphonist, d. 1809" , "Joseph -, Austr. composer (Farewell Symphony)" , "Classical composer" .)