Fail to agree on spinning music by One Direction (4)
I believe the answer is:
spar
'fail to agree' is the definition.
I can't judge whether this definition defines the answer.
'spinning music by one direction' is the wordplay.
'spinning' shows that the letters should be reversed in order.
'music' becomes 'rap' (I've seen this before**).
'by' means one lot of letters go next to another.
'one direction' becomes 's' (S is an example).
'rap'+'s'='raps'
'raps' back-to-front is 'SPAR'.
'on' acts as a link.
Can you help me to learn more?
(Other definitions for spar that I've seen before include "Do up (bird for oven)" , "Crystal - box" , "Scrap" , "Mast - boom - gaff" , "Fight - something probably rigged?" .)