Musician caught with drug, still shaky (7)
I believe the answer is:
cellist
'musician' is the definition.
(I know that cellist is a type of musician)
'caught with drug still shaky' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'with' indicates putting letters inside.
'drug' becomes 'e' (E is another name for ecstasy).
'shaky' indicates anagramming the letters.
'still' is an anagram of 'llist'.
'e' inserted inside 'llist' is 'ellist'.
'c'+'ellist'='CELLIST'
(Other definitions for cellist that I've seen before include "Member of orchestra" , "Musician in string section" , "Du Pre or Lloyd Weber" , "E.g. Casals, du Pre" , "Lloyd Webber?" .)