Lullaby composer (6)
I believe the answer is:
brahms
'lullaby composer' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for brahms that I've seen before include "German barman" , "'Bah, Mrs, he's a composer (6)'" , "Musician" , "German Romantic composer" , "He scored" .)