Daryl: Staying with science for the moment, in recent lectures in Norway you referred to experiments such as the «two-slit experiment» which have shaped your manipulation of musical material. Could you supply more detail on this, in respect to both the overall form of DARK MATTER and its specific movements?

Richard: What fascinates me most about the two-slit experiment is that an apparently simple procedure opens up problems and mysteries which bear on the nature of reality, our ability to perceive it, even whether reality consists of one or many universes. It's a classic demonstration of the dual nature of quantum objects like photons or subatomic particles, that is to say they appear like waves or like discrete particles, depending on how you decide to look at them. Single particles can somehow give rise to interference patterns, like those produced when interacting waves alternately reinforce and cancel one another.

The central part of DARK MATTER is entitled Ars Magna Lucis et Umbrae -- «the great art of light and shadow» -- after a work by the 17th-century Jesuit polymath Athanasius KIRCHER (a deeply fascinating, if decidedly unscientific, character). Here, this concept of interference appears in a number of ways. The interference between instrument and voice (by the same performer) in its solo part for contrabass clarinet is an obvious example. Also, there's a long passage where all the instruments are playing scales with gaps in them -- this material is generated by taking two scales and superimposing them in different ways, then removing (as if by wave-cancellation) those pitches which the two scales have in common. There's also a passage which relates to the operation of particle accelerators -- repeated «collisions» followed by an examination of the resulting fragments, which become more «unified» (into a melodic form) as the energy of the collisions increases. Also, the instrumentation of Ars magna  . . .  is mostly organised into pairs, where one instrument presents an «alternative existence», or shadow, to the other. There are plenty of further examples. But I'm not intending that they should all be «picked up» while listening, except as musical sound-structures; of course, the kinds of structure which are perceptible in music should be profoundly related to the kinds of structure we can perceive in other phenomena. And again, are we perceiving them or putting them there ourselves?