Star guest primarily vocalised (4)
I believe the answer is:
sung
'vocalised' is the definition.
'star guest primarily' is the wordplay.
'star' becomes 'sun' (Sun is an example).
'primarily' says to take the initial letters.
The first letter of 'guest' is 'g'.
'sun'+'g'='SUNG'
(Other definitions for sung that I've seen before include "Performed vocally; Chinese dynasty" , "Chinese dynasty; uttered melodiously" , "Celebrated dynasty" .)