Cut musical act (6)
I believe the answer is:
hairdo
'cut' is the definition.
(I've seen this before)
'musical act' is the wordplay.
'musical' becomes 'hair' (1960s musical).
'act' becomes 'do' (to do is to act or execute a task).
'hair'+'do'='HAIRDO'
(Other definitions for hairdo that I've seen before include "The process of styling head growth" , "Bob, perhaps" , "that may go with a bang?" , "Eg, beehive or mullet" , "capital arrangement" .)