One who will succeed with melody, we hear (4)
I believe the answer is:
heir
'one who will succeed' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'melody we hear' is the wordplay.
'melody' becomes 'air' (air can mean a tune or melody).
'we hear' indicates a 'sounds like' (homophone) clue.
'air' is a homophone of 'HEIR'.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for heir that I've seen before include "Beneficiary, inheritor" , "One set to inherit" , "One hoping to succeed" , "The first boy maybe" , "Successor to position or estate" .)