Prism III shows how the radiance of Bach's fugues is refracted through Beethoven's quartets to illuminate the work of later composers. "Beethoven had taken a fundamentally linear development from Bach," the Danes note, "and exploded everything into myriads of different colours, directions and opportunities - much in the same way as a prism splits a beam of light." They follow the beam from Bach's Fugue in c-sharp minor through Beethoven's String Quartet No.14 to Bartøk's String Quartet No.1.