Bay for encore to start after vocal performance (6)
I believe the answer is:
alcove
'bay' is the definition.
(synonyms)
'encore to start after vocal performance' is the wordplay.
'to start' says to take the initial letters.
'after' says to put letters next to each other.
'performance' indicates anagramming the letters.
The first letter of 'encore' is 'e'.
'vocal' with letters rearranged gives 'alcov'.
'e' after 'alcov' is 'ALCOVE'.
'for' is the link.
(Other definitions for alcove that I've seen before include "Small opening - a clove (anag)" , "nook" , "Small opening off a larger room" , "sheltered spot" , "bay" .)