Magic word appeals to audience (6)
I believe the answer is:
please
'magic word' is the definition.
'please' can be an answer for 'word' (I have seen 'Polite word' mean 'please' so perhaps 'word' could also mean 'please'). I'm not certain of the 'magic' bit.
'appeals to audience' is the wordplay.
'appeals' becomes 'pleas' (plea is a kind of appeal).
'to audience' indicates a 'sounds like' (homophone) clue (how it might sound to an audience).
'pleas' is a homophone of 'PLEASE'.
Can you help me to learn more?
(Other definitions for please that I've seen before include "Polite addition to a request" , "Be good enough to" , "Entertain" , "Give happiness" , "Satisfy aesthetically" .)