Smoothly, on a score (6)
I believe the answer is:
legato
'smoothly on a score' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for legato that I've seen before include "Got ale (anag.)" , "In music, in a smooth even manner" , "Smoothly-flowing" , "scored smoothly" , "Smoothly flowing in style" .)