Charmed by song in terrible need (9)
I believe the answer is:
enchanted
'charmed' is the definition.
(similar in meaning)
'song in terrible need' is the wordplay.
'song' becomes 'chant' (song sung by a crowd).
'in' is an insertion indicator.
'terrible' is an anagram indicator.
'need' anagrammed gives 'ened'.
'chant' inserted inside 'ened' is 'ENCHANTED'.
'by' acts as a link.
(Other definitions for enchanted that I've seen before include "Beguiled" , "Put under spell" , "Delighted, charmed" , "delighted by spelling" , "Bewitched" .)