Fantastic idea: put on Mozart's KV 365 for example (5,4)

I believe the answer is:

piano duet

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'mozart's kv 365 for example' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'fantastic idea put on' is the wordplay.
'fantastic' indicates an anagram (a fantastic or improbable ordering of the letters).
'idea'+'put'+'on'='ideaputon'
'ideaputon' is an anagram of 'PIANO DUET'.

Can you help me to learn more?

(Another definition for piano duet that I've seen is " Keyboard composition".)

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