Composer of The Messiah (6)
I believe the answer is:
handel
'composer of the messiah' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for handel that I've seen before include "Anglo-German composer" , "German composer, lived in England" , "Sounds as if you could come to grips with this composer" , "Composer of Messiah, d.1759" , "German baroque composer" .)