It's connected to cue lights in other departments. Light on means "warning" (get ready for some action) and light off means "go" (do the action now). The actions are written on the script.
No, the Stage Manager is calling for the lights, sound, and automation operators. Occasionally the SM will communicate with the maestro, and sometimes with deck crew (the people in the wings). The only time the actors can hear the SM is when they're calling times (i.e., half hour to the top of the show, 5 minutes, places).
The switches turn cue lights on and off for crew running automation (motorized scenery) and the flyrail (things that fly in or out). When the light goes on, that's their warning that a cue is coming up soon. When he flips the switch off their cue light goes out and that means "go."
Krista Carlson it’s most definitely lights lol. That’s what a stage manager does. He’s saying “Lights--“ whatever. And at some points he’s saying standby or “on deck” meaning to prep the upcoming lights for the light board operator.
