Heavy metal show (4)
I believe the answer is:
lead
I believe this is a double definition.
'heavy metal' is the first definition.
(I've seen this before)
'show' is the second definition.
(thesaurus)
(Other definitions for lead that I've seen before include "Guide; precede" , "Main news story" , "Guide; graphite" , "Precede into dale" , "Soft, heavy metal" .)