Artist in the modern style (5)
I believe the answer is:
ernst
'artist' is the definition.
(max ernst)
'in the modern style' is the wordplay.
'in' indicates a hidden word.
'ERNST' can be found hidden inside 'modern style'.
(Other definitions for ernst that I've seen before include "Max __; Dadaist" , "artist's name" , "He painted" , "German-born painter, Max, co-founder of dadaism, d. 1976" , "Surrealist; stern (anag.)" .)