"The Lighthouse" is an orchestral piece from the Season 6 soundtrack.
At the top of the lighthouse, Jack and Hurley discover a wheel surrounding a fire bowl and a series of mirrors. Hurley starts turning the wheel, and Jack sees his childhood home briefly reflected in the mirrors. He then notices their names on the lighthouse dial and realizes Jacob has been watching him for years. When Hurley refuses to produce Jacob, Jack goes into a rage and smashes the mirrors.