Boy in song (5)
I believe the answer is:
danny
'boy in song' is the definition.
'Danny' can be an answer for 'boy'. I am not certain of the 'in song' bit.
'boy in song' is the wordplay.
'boy' becomes 'Dan'.
'in song' becomes 'ny' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'dan'+'ny'='DANNY'
Can you help me to learn more?
(Other definitions for danny that I've seen before include "- Kaye, US actor" , "Boy, Kaye or Blanchflower" .)