Party's very loud in shed (4)
I believe the answer is:
doff
'shed' is the definition.
(I've seen this before)
'party's very loud' is the wordplay.
'party' becomes 'do' (do is a kind of party).
'very loud' becomes 'ff' (musical abbreviation).
'do'+'ff'='DOFF'
'in' is the link.
(Other definitions for doff that I've seen before include "Remove one's cap" , "Lift (one's hat)" , "shed" , "Take off (clothing) - remove (hat)" , "Remove, hat say" .)