Soft-hearted idol forged a graduate qualification (7)
I believe the answer is:
diploma
'qualification' is the definition.
(type of academic qualification)
'soft-hearted idol forged a graduate' is the wordplay.
'soft' becomes 'p' (musical abbreviation for 'piano').
'hearted' means one lot of letters goes inside another (some letters go to the heart of the word).
'forged' indicates anagramming the letters.
'a graduate' becomes 'MA' (abbreviation for Master of Arts).
'idol' is an anagram of 'dilo'.
'p' put into 'dilo' is 'diplo'.
'diplo'+'ma'='DIPLOMA'
(Other definitions for diploma that I've seen before include "degree certificate" , "Academic award" , "official document" , "Certificate of education" , "Degree document" .)