They pass into that music:
I too in sleep have heard
The harmony sublime
And known myself among the blessed dead.
We cannot walk the waves they tread,
To sense this story ground:
They hear as music what we feel as pain.

Kathleen Raine's recent poem was amongst the early entries in the section of my notebook dealing with Inner Light (3). The three-part sequence of works is a sort of homage to Rudolf Steiner, who, together with countless poets and religious men, has written about 'that music', as well as about many other things which fascinate me. The sequence consists of three works for tape and live performers; it expands from chamber ensemble to chamber orchestra with voices to full orchestra. In the first work the tape is used to transform, by subtle inner changes, from instrumental timbre to structural harmony, in the second from vowel sounds to harmony and instrumental timbre, and in the third from one instrumental timbre into another. All three start with a long, dark passage out of which the sound world arises. The third is concerned with expansion itself, a reflection of the basic idea of the expansion of the consciousness towards God.

My music has increasingly been concerned with a quest for structural depth (in the Schenker tradition maybe). This means that several levels of structure are inextricably woven together in a 'nest', ranging from all the details and embellishment at the top to the single macrocosmic idea at the bottom. Thus, the idea of 'expansion' occurs on many levels; I will mention the most important to illustrate the point.

Level 1. Basic set - expansion (and contraction) of intervals (contraction in the retrograde, and also within the set as the second half retrogrades the first). Six forms of this set are given in a string of long notes stretching, with interruptions, across the entire length of the piece.

Level 2. Many 12-note derived sets forming the main substance of the sound. They concentrate on one or two intervals at a time, going through the intervals of level 1 in order, e.g. first the semitonal sets then the whole tone sets etc.

Level 3. Musical spaces or harmonic fields - repertories of pitches through which the music can move - ranging from the normal dense semitonal division of space to a rarefied tritonal one. A second system continues to expand outwards at the point where the first starts to contract from the tritone inwards again, giving a background sequence of ever wider intervals which peep through the gaps in the texture, so that fewer and fewer pitches can be contained in the audibility range. Eventually only two are left, which slide off the high and low limits respectively into silence.

In four places there is a constriction beyond the semitone, to quartertones and on into the noise domain. These four sections have a large element of untuned percussion in them.

The instrumentation reflects the mirror structure of the Basic Set. The number of instrument types playing the main musical foreground at any time depends on Level 2 - on the number of pitches in the segment (expanding from 1 - 5 over the whole work) being exploited in the current derived set. In other words, an instrument or instruments are attached to each pitch of the Basic Set. Having entered in each of the main sections (XYZ) instruments stay in, accumulating in number, but as accompaniment, providing 'clouds' and subsidiary figures more freely composed within the current harmonic 'space'. So each section expands timbrally.

Cutting right across all this is the instrumentation of Level 1, the 'cantus firmus', which is played more slowly in the order of the first twelve instrument-types.

The organisation of the rhythm is analogous. Again it is linear and easy to hear, things get steadily faster or slower, durations steadily expand and contract, and the number of durations increases or decreases around 12. In section X the tempi (written out against the conductor's constant beat) move from slow to fast. In Y they start at medium tempo and get alternatively slower and faster. In Z they again expand the interval between them, starting almost together in the medium tempo range, but the two tempi are played simultaneously. The difference between them continues to expand to the end of the piece where the slow tempo is articulated by widely separated loud chords and the instruments, playing as fast as possible, evaporate in a whirling rush of wind shooting off around the hall.

The piece constantly strives to expand to this tempo, enticed on by the tape. One of the tapes other roles is to transform one instrument's waveform into another's, often in the course of a journey round the concert hall. For instance, a trumpet sound leaves the orchestra, changes progressively into a clarinet in mid-flight, so to speak, and returns to the stage area where the orchestral clarinet takes it up. The spatial engulfment of quadraphony and the dreamlike reverberation of orchestral events are, together with the alpha wave treatment, further aspects of the 'superhuman' role of the tape. There is nothing new in regarding the mechanical as superhuman; everyone in Western tradition who has ever thought of the organ as a bearer of sacred meaning, or in the East of the gong in such a light has done the same.

I have drawn attention mainly to the background structures and principles, which would normally only become clear after a few hearings, in the hope that the foreground events will speak for themselves and need no surround of words. I see no other way of defending my faith in structural depth in a post-tonal world Schenker would undoubtedly have regarded as anathema.