You can assign an interest, or “look-at point” for any light.

To define a light’s interest:

1. Select the light in either the Scene browser or the Viewer window.
2. In the Light Settings, Alt-drag any element into the Interest field to define it as the interest of a given light.
3. If you translate the interest object, the light is constrained to it.
   

   Spot light interest A. Spot light with Interest not set. B. Spot light with Interest set on the guitar.

Click the Interest field to select the element you selected to be the light’s interest, and both the light and interest object are selected. When the light is translated, the light’s interest follows it.