Perhaps South Pacific island's captured by surprisingly calm US (7)
I believe the answer is:
musical
'perhaps south pacific' is the definition.
Both the definition and answer are adjectives. Perhaps they are linked in a way I don't understand?
'island's captured by surprisingly calm us' is the wordplay.
'island' becomes 'i' (geographical abbreviation).
'captured by' is an insertion indicator.
'surprisingly' indicates an anagram (a surprising ordering of the letters).
'calm'+'us'='calmus'
'calmus' is an anagram of 'muscal'.
'i' placed into 'muscal' is 'MUSICAL'.
Can you help me to learn more?
(Other definitions for musical that I've seen before include "Eg, Cats or Evita" , "Staged entertainment" , "Eg, Les Miserables" , "Cats perhaps" , "Song and dance show" .)