"Goldberg Variations" composer (4)
I believe the answer is:
bach
'goldberg variations composer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bach that I've seen before include "endearing Welsh appellation" , "German organist and composer, d. 1750" , "Johann Sebastian . . . . , great composer (4)" , "German composer, who had twenty children, d.1750" , "J. S. -, Ger. composer" .)