Life magazine holds competition, with article, to compose hymn (7,5)
I believe the answer is:
amazing grace
'hymn' is the definition.
(I've seen this before)
'life magazine holds competition with article to compose' is the wordplay.
I cannot really understand how this works, but
'competition' could be 'race' (race is a kind of competition) and 'race' is found within the answer.
'article' could be 'a' (English indefinite article) and 'a' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for amazing grace that I've seen before include "Noted words of praise" , "knocking cricketer for six?" , "song" , "Hymn that "sav'd a wretch like me"?" , "religious air" .)