Change of mood in jazz-like music? (5)
I believe the answer is:
swing
I believe this is a double definition.
'change of mood' is the first definition.
(mood swing)
'jazz-like music?' is the second definition.
'in' is the link.
(Other definitions for swing that I've seen before include "in the park?" , "Big band jazz" , "Jaunty rhythm in music" , "1930s' big band dance music - playground feature" , "Type of music" .)