Musician stranger after last of LSD (7)
I believe the answer is:
drummer
'musician' is the definition.
(I know that drummer is a type of percussionist)
'stranger after last of lsd' is the wordplay.
'stranger' becomes 'rummer' (rum can mean strange).
'after' is a charade indicator (letters next to each other).
'last of' says to take the final letters.
The final letter of 'lsd' is 'd'.
'rummer' put after 'd' is 'DRUMMER'.
(Other definitions for drummer that I've seen before include "salesman to America" , "One using sticks" , "Timpani beater" , "Gene Krupa, say" , "Someone who keeps 18 [RHYTHM]" .)