A trailer brake system status indicator is provided to a tractor driver. The motion detection apparatus may output a final motion flag in accordance with whether there is motion in a black-and-white image, whether there is first color motion in a color image, and whether there is second color motion in the color image. The imaging subsystem is capable of providing image data representative of light incident on said imaging subsystem. For example, a neighborhood of songs may be determined within which each song has a similar consonance.