Act in rotation (4)
I believe the answer is:
turn
This clue is a double definition.
'act' is the first definition.
(a routine or performance)
'in rotation' is the second definition.
(thesaurus)
(Other definitions for turn that I've seen before include "Move in a new direction" , "Move around an axis, or change" , "(Of tide) change from flood to ebb" , "See 19" , "Revolution by runt" .)