Graphite, not soft, brings complaint (7)
I believe the answer is:
lumbago
'complaint' is the definition.
(I've seen this before)
'graphite not soft' is the wordplay.
'graphite' becomes 'plumbago' (synonyms).
'not' suggests deleting specific letters.
'soft' becomes 'p' (musical abbreviation for 'piano').
'plumbago' with 'p' taken out is 'LUMBAGO'.
'brings' acts as a link.
(Other definitions for lumbago that I've seen before include "Lower back ache" , "Back problem" , "Maul bog badly for a rheumatic affliction" , "Rheumatic pain in the small of the back" , "Back affliction" .)