Bird duets raucously, creating upset (9)

I believe the answer is:

disturbed

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

'upset' is the definition.
(I know that upset can be written as disturbed)

'bird duets raucously' is the wordplay.
'bird duets' anagrams to 'DISTURBED'.
But, I'm not sure how the anagram is indicated.

'creating' acts as a link.

Can you help me to learn more?

(Other definitions for disturbed that I've seen before include "Troubled" , "Intruded on" , "Interrupted" , "Agitated" , "Changed the set arrangement or made uneasy" .)

I've seen this clue in The Sun.

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