John of music (5)
I believe the answer is:
elton
'john of music' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for elton that I've seen before include "First name of singer/songwriter born Reginald Dwight in 1947" , "Ben --; -- John" , "Let on he's John, the singer" , "Sir ___ John, singer-songwriter" , ". . . . . John (musician)" .)