Discovered tune heard in composition (9)
I believe the answer is:
unearthed
'discovered' is the definition.
(I've seen this in another clue)
'tune heard in composition' is the wordplay.
'in composition' is an anagram indicator (letters composed or arranged differently).
'tune'+'heard'='tuneheard'
'tuneheard' anagrammed gives 'UNEARTHED'.
(Other definitions for unearthed that I've seen before include "Excavated, brought to light" , "unsafe condition of electrical apparatus" , "found" , "Discovered something hidden by digging" , "Dug up" .)