The main hazard for an experimental composer (4)
I believe the answer is:
berg
This might be a double definition.
'the main hazard' is the first definition.
(iceberg - main can mean the sea)
'an experimental composer' is the second definition.
'berg' can be an answer for 'composer' (Alban Berg, 1885 - 1935). I am not sure about the 'an experimental' bit.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for berg that I've seen before include "South African mountain - Austrian composer" , "Mountain (in German, South African)" , "feature of icy waters" , "Alban ----, composer of the incomplete opera 'Lulu' (1935)" , "Small version of ice mountain" .)