Perfect organ composition by father (7)
I believe the answer is:
paragon
'perfect' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'organ composition by father' is the wordplay.
'composition' indicates anagramming the letters (letters arranged or composed in a different order).
'by' means one lot of letters go next to another.
'father' becomes 'pa' (pa can mean dad or father).
'organ' is an anagram of 'ragon'.
'ragon' after 'pa' is 'PARAGON'.
Can you help me to learn more?
(Other definitions for paragon that I've seen before include "Perfect type" , "Model of conduct" , "Very good example" , "A Model of excellence, perfect person" , "A perfect person - pagan or what?" .)