Make the locks secure and calm down! (4,4,4,2)
I believe the answer is:
keep your hair on
'make' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'locks secure and calm down' is the wordplay.
I cannot really see how this works, but
'locks' could be 'hair' (locks can mean hair) and 'hair' is found within the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
This explanation may well be incorrect...
'the' is the link.
(Other definitions for keep your hair on that I've seen before include "Still be shocked" , "Remain calm!" .)