Painter contributing to modern style (5)
I believe the answer is:
ernst
'painter' is the definition.
(Max Ernst)
'contributing to modern style' is the wordplay.
'contributing to' indicates a hidden word (the answer contributes to part of the clue ).
'ERNST' is hidden within 'modern style'.
(Other definitions for ernst that I've seen before include "He painted" , "Max __; Dadaist" , "Young partner" , "German-born painter, Max, co-founder of dadaism, d. 1976" , "artist's name" .)