Composer Bela (6)
I believe the answer is:
bartok
'composer bela' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bartok that I've seen before include "Bela ------ (1881-1945), Hungarian composer" , "Hungarian composer of folk music" , "Bela -, nineteenth and twentieth century Hungarian composer" , "classical composer" , "Bela -, Hung. composer" .)