A keyboard is able to illuminate particular keys and to detect keypresses in an efficient manner. The keys of the array are logically arranged into one or more two-dimensional arrays (e.g., row/column arrays) so that the illumination and keypress detection functions share a common set of electrical signal lines in one dimension of the array. By coupling both the lights and the key actuation switches of each key to a common set of signal lines in one dimension, the number of signal lines used in the keyboard can be reduced.