What is the term used for the transition from one lighting or sound cue to another without interruption?

The correct term for the transition from one lighting or sound cue to another without interruption is "crossfade." This technique is commonly used in theatrical productions to create a seamless shift between different audio and visual elements, enhancing the flow of the performance and ensuring that there are no abrupt changes. A crossfade allows one sound or lighting state to gradually blend into another, which can help maintain the audience's engagement and the overall mood of the scene.

In contrast, "fade up/down" refers to the gradual increase or decrease of lighting or sound levels but does not specifically imply a simultaneous transition between two cues. "Spotlight" refers to a specific type of lighting used to emphasize a particular actor or area of the stage, while "focussing" pertains to adjusting lighting instruments to achieve the desired beam spread or intensity. These terms do not denote the smooth transition characteristic of a crossfade.