Note about a popular song in S Pacific island (6)
I believe the answer is:
tahiti
's pacific island' is the definition.
'note about a popular song' is the wordplay.
'note' becomes 'ti' (I've seen this in other clues**).
'about' means one lot of letters goes inside another.
'popular song' becomes 'hit'.
'a'+'hit'='ahit'
'ti' enclosing 'ahit' is 'TAHITI'.
'in' acts as a link.
(Other definitions for tahiti that I've seen before include "An isle in the South Seas" , "South Pacific island, associated with Robert Louis Stevenson" , "Pacific island, Gauguin's home in the 1890s" , "I hit at the tropical island" , "South Pacific island, linked to Paul Gauguin and Robert Louis Stevenson" .)