Unmusical drunk fed at one (4,4)

I believe the answer is:

tone deaf

I'm a little stuck... Click here to teach me more about this clue!

'unmusical' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?

'drunk fed at one' is the wordplay.
'drunk' indicates anagramming the letters.
'fed'+'at'+'one'='fedatone'
'fedatone' is an anagram of 'TONE-DEAF'.

Can you help me to learn more?

(Other definitions for tone deaf that I've seen before include "not appreciative of notes?" , "no ear?" , "insensitive to pitch" .)

I've seen this clue in The Daily Express.

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