A little pasta or jam? (6)
I believe the answer is:
noodle
This clue is a double definition.
'a little pasta' is the first definition.
(noodles are a type of pasta)
'jam?' is the second definition.
(both can mean to improvise musically)
'or' acts as a link.
(Other definitions for noodle that I've seen before include "Nitwit" , "Egg pasta" , "Ribbon-like strip of pasta" , "Head - simpleton - found in soup" , "Fool (in the soup?)" .)