Nut excited by English melody (4)
I believe the answer is:
tune
'melody' is the definition.
('tune' can be a synonym of 'melody')
'nut excited by english' is the wordplay.
'excited' indicates anagramming the letters.
'by' means one lot of letters go next to another.
'english' becomes 'e' (abbreviation).
'nut' anagrammed gives 'tun'.
'tun'+'e'='TUNE'
(Other definitions for tune that I've seen before include "temper" , "Adjust for better performance" , "Of engine, adjust to run smoothly" , "strain" , "Optimise the condition of" .)