Musical party style (6)
I believe the answer is:
hairdo
'style' is the definition.
(I know that style can be written as hairdo)
'musical party' is the wordplay.
'musical' becomes 'hair' (1960s musical).
'party' becomes 'do' (do is a kind of party).
'hair'+'do'='HAIRDO'
(Other definitions for hairdo that I've seen before include "Bob, for one" , "Coiffure (colloq.)" , "Cut and set" , "Barnet" , "Styling of the locks" .)