Boy finds German tune (4)
I believe the answer is:
song
'tune' is the definition.
(I've seen this in another clue)
'boy finds german' is the wordplay.
'boy' becomes 'son' (male child).
'finds' means one lot of letters go next to another.
'german' becomes 'g' (abbreviation).
'son'+'g'='SONG'
(Other definitions for song that I've seen before include "Ballad, aria" , "Vocal item" , "Ditty" , "Musical composition; air" , "You work best when on this" .)