Hemlock Stone (2004) is something of an outlier, inasmuch as it is the only piece in this collection composed using tools developed by the Composer’s Desktop Project. Founded in 1986 with Orton amongst its founding members, the CDP is, according to Wishart, ‘a composers' cooperative [which] expanded and contracted at various times, morphed into a small business, then back into a cooperative’. Over the course of its 35 year existence, it has been responsible for generating a ‘vast collection of non-real time signal processing software’.

The CDP developed from the converging interests of members of the Yorkshire electroacoustic composers discussion group, INTERFACE, which met for the first time in the autumn of 1982 and included Orton, Wishart, Hearn, Malham, Christopher Fox, Archer Endrich, and Phil Ellis. In its earliest meetings, Orton demonstrated a number of music programmes he had developed for the Sharp MZ-80A - ‘programs to create sub-harmonic series, swirling glissandi, Partch’s 43-note scale, permutations, and other controlled glissandi’ - having maintained an interest in computer-aided composition since the mid-1970s. At the same time, Wishart and Geoff Beacon had established a company, ‘Convivial Tools’, with a view to collaborating with Malham on the development of signal processing tools.

CDP resulted at once from the impracticalities posed by the University of York Music Department’s minicomputer running CSound in the mid 1980s, and the concurrent explosion in microprocessing which led to the reimagination of the Atari ST personal computer as a potential desktop tool for composition - ‘with a little technical help’. Orton’s contribution to the CDP was significant: a collaboration with Ross Kirk of the university’s Electronics Department on the Musical Instrument Digital Array Signal Processor (MIDAS) Project ultimately led to the development of Tabula Vigilans, a rule-based algorithmic composition system which underscores much of the composer’s later work, including The Hemlock Stone.

The source of the piece can be traced to a journal entry in late May 2004, in which Orton reflects on a visit to Greece during which he passed the Volax monolith at Tinos, en route to Pyrgos and Panormos: ‘I have had confirmed for me the notion of making an electronic piece based on the idea of three monoliths’, he wrote. This triptych was to explore an evolution of textures sourced from rock and stone, with the location of each to be chosen in order to ‘encompass my world in a satisfying way’. Orton had already identified the Hemlock Stone on Stapleford Hill in the Nottinghamshire of his childhood as the first of the locations, and planned a third component based around Pulpit Rock, a sandstone tower near Blackheath at the western end of the Australian Blue Mountains.

The Hemlock - or Himlack - Stone is a 30-foot high red sandstone outcrop dating from the Triassic period, on Stapleford Hill in Nottinghamshire. It is an inselberg - an isolated feature rising from a plain - and is believed to be the surviving remnant of a period of intensive sandstone quarrying. Very much in opposition to D.H. Lawrence’s portrayal of the stone in Sons and Lovers as a ‘little, gnarled, twisted stump of rock, something like a decayed mushroom, standing out pathetically on the side of a field’, Orton found resonance in the ‘masculine, even phallic, energy’ in the formation, an energy ‘which has escaped - perhaps [in the form of] a dragon’.

If the composer was intrigued by the possibility of working with monolithic sites steeped in history and folklore, his interest was not confined to the symbolic, and Orton remained fascinated by the possibility of capturing and processing complex sounds generated by striking stone, noting in his journal that ‘it occurred to me that I could record these sounds and process them as inharmonic mixtures through the phase vocoder’. As such, Hemlock Stone revisits an acute compositional concern for the synthesis of rich material exploration and symbolic content characteristic of Orton’s earlier work for tape.