Since the main component in the theater is the Yamaha receiver, that is what we will center the choices around. There are 7 choices Mary has to choose from when selecting an input for the Yamaha:
There is one main event that makes calls to several other events called "Soundsys Selector". This event can be called from many different places within ECS such as button presses on a keypad, clicks on an icon either from the ECS application or the built in web page, or any number of other events like the Sunrise Timer that slowly turns up the lights in the master bedroom so the occupants can be gently awakened. About half way through this routine of turning up the lights the stereo is turned on and the tuner is chosen using the Soundsys Selector event.