Note was transposed - it's nothing (2,5)
I believe the answer is:
no sweat
'nothing' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'note was transposed' is the wordplay.
'transposed' indicates an anagram.
'note'+'was'='notewas'
'notewas' anagrammed gives 'NO SWEAT'.
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for no sweat that I've seen before include "Don't worry" , "easily done" , "That's a piece of cake (anti-perspirant unnecessary!)" , "Not a problem! (informal)" , "That won't be a problem" .)