Respond about performance (5)
I believe the answer is:
react
'respond' is the definition.
(to react to something is to respond to it)
'about performance' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'performance' becomes 'act' (act is a kind of performance).
're'+'act'='REACT'
(Other definitions for react that I've seen before include "provide an answer" , "Respond emotionally" , "Hit back" , "What a chemical might do" , "Change chemically" .)