Smooth transition (5)
I believe the answer is:
segue
'smooth transition' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for segue that I've seen before include "Follow on without a pause" , "Go on without interruption" , "Change smoothly from one thing to another" , "Move between songs, etc, without a pause" , "Move continuously from one song to another" .)