Have a little break for a little jazz (4,4)
I believe the answer is:
take five
'a little jazz' is the definition.
Although both the answer and definition are verbs in their base form, I can't see how they can define each other.
'have a little break' is the wordplay.
'have' becomes 'take' (taking is a kind of having).
'a little break' becomes 'five' (I can't justify this - if you can you should believe this answer much more).
'take'+'five'='TAKE FIVE'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for take five that I've seen before include "Invitation to break" , "after four attempts at recording?" , "Enjoy the rest!" , "Have a short break (by Brubeck?)" , "Have a break (colloq.)" .)