Heavy metal from humble admirer (4)
I believe the answer is:
lead
'heavy metal' is the definition.
(lead is a heavy metal)
'from humble admirer' is the wordplay.
'from' says the answer is hidden in the clue.
'LEAD' can be found hidden inside 'humble admirer'.
(Other definitions for lead that I've seen before include "Church windows include this" , "Travel in front of" , "One with starring role" , "Go ahead; element" , "Call the shots" .)