Vocal performance with energy in recess (6)
I believe the answer is:
alcove
'recess' is the definition.
(I know that alcove is a type of recess)
'vocal performance with energy' is the wordplay.
'performance with' indicates anagramming the letters.
'energy' becomes 'e' (physics symbol as in E=mc2).
'vocal' with its letters mixed up with 'e' makes 'ALCOVE'.
'in' is the link.
(Other definitions for alcove that I've seen before include "Small opening - a clove (anag)" , "nook" , "Recessed part of a room" , "Recessed area" , "Small recess in a larger room" .)