Composer angrily rails at heartless court (9)
I believe the answer is:
scarlatti
'composer' is the definition.
(I've seen this before)
'angrily rails at heartless court' is the wordplay.
'angrily' indicates an anagram (I've seen this in other clues).
'heartless' suggests removing the centre.
'court' with its middle taken out is 'ct'.
'rails'+'at'+'ct'='railsatct'
'railsatct' is an anagram of 'SCARLATTI'.
(Other definitions for scarlatti that I've seen before include "Seventeenth to eighteen cetury Italian composer (father or son)" , "opera producer" , "Italian scoring" , "Alessandro and Domenico --, Italian composers" , "scorer" .)