What Ian needs to make him a player (5)
I believe the answer is:
music
'what ian needs to make him a player' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'him a player' is the wordplay.
I cannot quite see how this works, but
'him' could be 'si' and 'si' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for music that I've seen before include "Strains" , "melodies" , "A score represents it" , "Harmonious sound (generally!)" , "'Fled is that ---: do I wake or sleep?' (Keats)" .)