Opposite of staccato (6)
I believe the answer is:
legato
'opposite of staccato' is the definition.
('legato' is the opposite to 'staccato')
This is the entire clue.
(Other definitions for legato that I've seen before include "In music, the opposite of staccato" , "Got ale (anag.)" , "Smoothly (musical)" , "In a smooth and flowing manner (music)" , "play on without pause" .)