RulerOf writes "Musicians recently unlocked a 600 year old mystery that had been encoded into the walls of the Rosslyn Chapel in Scotland, the one featured in The Da Vinci Code. The song was carved into the walls of the chapel in the form of geometric shapes that a father-son team — both are musicians and the father is an ex-Royal Air Force code breaker — finally matched to so-called Chladni patterns (see the Wikipedia article on cymatics). The recovered melody was paired with traditional lyrics (translated into Latin) and recorded; the result can be heard in this video (also linked from the musicians' website). The video also gives a visual representation of how the engravings match up to the cymatic patterns."
From the Reuters article: "'The music has been frozen in time by symbolism... [The carvings] are of such exquisite detail and so beautiful that we thought there must be a message here.' The two men matched each of the patterns on the carved cubes to a Chladni pitch, and were able finally to unlock the melody."