Beg for introduction to punk and heavy metal (5)
I believe the answer is:
plead
'beg' is the definition.
(I know that beg is a more specific form of plead)
'introduction to punk and heavy metal' is the wordplay.
'introduction to' says to take the initial letters.
'and' is a charade indicator (letters next to each other).
'heavy metal' becomes 'lead' (lead is a heavy metal).
The first letter of 'punk' is 'p'.
'p'+'lead'='PLEAD'
'for' acts as a link.
(Other definitions for plead that I've seen before include "Claim; entreat" , "advocate in court" , "Argue (a position in court)" , "Respond to charge" , "Supplicate" .)