Heavy metal featured guitar (4)
I believe the answer is:
lead
This clue might be a double definition.
'heavy' is the first definition.
(thesaurus)
'metal featured guitar' is the second definition.
'lead' can be an answer for 'metal' (I've seen this in another clue). I'm not sure about the 'featured guitar' bit.
Can you help me to learn more?
(Other definitions for lead that I've seen before include "Church windows include this" , "front man" , "Starring role - kind of pencil" , "Chemical element, symbol Pb" , "pioneer" .)