Mo Ali sits around getting very high (9)
I believe the answer is:
altissimo
'very high' is the definition.
(musical term)
'mo ali sits around' is the wordplay.
'around' indicates anagramming the letters.
'mo'+'ali'+'sits'='moalisits'
'moalisits' with letters rearranged gives 'ALTISSIMO'.
'getting' acts as a link.
(Other definitions for altissimo that I've seen before include "Very highly pitched" , "one is almost dizzy" , "Very highly placed" , "Very high musical pitch" .)