Edinburgh-based composer Stuart Mitchell believes he may have found the key to unlocking the secret of Rosslyn's treasure in an unusual form of musical notation. In fact, the idea came from Mitchell’s father, Thomas, who has spent some 20 years grappling with the chapel’s mysteries and now believes he has at last cracked the Rosslyn 'code'. The series of carved cubes high up in the building's Lady Chapel are, he believes, a cryptic form of musical notation, in which the patterns carved on the cubes' faces represent the equivalent of Chladni patterns, with different frequencies producing different shapes, including flowers, rhomboids, diamonds and hexagons – all of which are to be seen on the mysterious cubes.

For Stuart Mitchell this goes "beyond coincidence" and he has been arranging and orchestrating the musical patterns unearthed by his father into his latest composition, The Rosslyn Motet. Mitchell sees Rosslyn’s link with the Knights Templar as the likely explanation for the encrypted music, and believes that they may have learned some of the secrets of sound a long time before Ernst Chladni: "What it points towards is the Church system denying people certain knowledge because knowledge is awareness. People who knew too much were burnt as witches."

And other proscribed knowledge is present, argues Mitchell, in the Devil’s Chord, which features heavily in the Rosslyn cube patterns: "In the ceiling is this jump of an augmented fourth, in fact it opens up with an augmented fourth."

The plan is to play the music on mediæval instruments within the chapel itself, where the resonating frequencies of the music will unlock a secret within the stones of Rosslyn itself: "Hopefully, knowing masons of this period were aware of the acoustic properties and the effect of resonance upon stone, we’re hoping something falls loose… it’s like a safe. This is why we think he [Sir William St Clair] has gone to so much trouble." The Scotsman, 27 Apr 2006; www.stuart-mitchell.com