Playing marimba's OK, Peter Pan-style (4,6)

I believe the answer is:

arms akimbo

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

'peter pan-style' is the definition.
I know nothing about this answer so I can't tell whether this works.

'playing marimba's ok' is the wordplay.
'playing' is an anagram indicator.
'marimbas'+'ok'='marimbasok'
'marimbasok' anagrammed gives 'ARMS AKIMBO'.

Can you help me to learn more?

I've seen this clue in The Guardian.

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