Musical slidings are slidings with a difference (9)
I believe the answer is:
glissandi
'musical slidings' is the definition.
I can't judge whether this defines the answer.
'slidings with a difference' is the wordplay.
'with' is a charade indicator (letters next to each other).
'difference' is an anagram indicator.
'slidings'+'a'='slidingsa'
'slidingsa' is an anagram of 'GLISSANDI'.
'are' is the link.
Can you help me to learn more?
(Other definitions for glissandi that I've seen before include "Players may perform them" , "Slides (music)" , "Series of rapidly ascending or descending musical notes" , "Musical terms" , "playing, while sliding up and down the passages" .)