Somewhat cacophonous, a shocking band (4)
I believe the answer is:
sash
'band' is the definition.
(sash is a kind of band)
'somewhat cacophonous a shocking' is the wordplay.
'somewhat' says the answer is hidden in the clue.
'SASH' is hidden within 'cacophonous a shocking'.
(Other definitions for sash that I've seen before include "Strip of cloth - type of window" , "Popular band in Northern Ireland" , "Framework to hold the panes of a window" , "Brown bread for waist or shoulder" , "Window frame - shoulder band" .)