You are designing the audio system for a chain of pizza restaurants that play background music. Each restaurant also contains a jukebox for customer use. If a customer purchases a song, the restaurant owners want that song to play immediately—with no intervention needed by anyone. When the jukebox stops playing, the background music should fade in again.
To implement this requirement, you decide to configure the jukebox as a priority input so that when it starts playing, HAL will mute the background music, and when it stops playing, HAL will play the background music again. Because no intervention is needed, there is no need for remote control hardware (except, perhaps, to control volume).
This simple scenario requires two inputs, one for the background music and one for the jukebox. Although we are creating only one zone for this restaurant, we'll use the Distributed Program Bus for the background music. Then, if we add more zones later, the background music inputs will automatically be included in those zones.
That's all you have to do to configure the jukebox as a higher priority input over the background music. When HAL detects a signal coming from the jukebox, it will mute the background music and play the jukebox input. When the jukebox signal stops, HAL will unmute the background music, fading it back in based on the Ramp Back value.