Race of theatre goers (4)
I believe the answer is:
heat
'race' is the definition.
(I know that heat is a type of race)
'of theatre goers' is the wordplay.
'of' indicates the answer is hidden within the clue.
'HEAT' is hidden in the letters of 'theatre goers'.
(Other definitions for heat that I've seen before include "Vehemence" , "Get agitated" , "Level of spice" , "eliminating round" , "Pressure" .)