"A Just 
                Cause" 
              
 
              
© 
                Paul Serotsky 1998, 2004 
              
 
             
                
1	Introduction 
                
 
                
"What rubbish!" 
                  Two little words of deprecation, hardly 
                  an auspicious start to a train of 
                  events which was to transform my attitude 
                  to music. I heard them from a lady 
                  sitting just behind me at a presentation 
                  given, in 1976, by a representative 
                  of a record distributor. We had just 
                  heard an extract from one of the CRI 
                  (Composers' Recordings Incorporated) 
                  records his company was then marketing 
                  in this country. To be fair, the lady 
                  was merely giving voice to an opinion 
                  held by many, if not most, of the 
                  audience. However, I have to admit 
                  that I find it intensely aggravating 
                  when an extended musical work is summarily 
                  dismissed on the strength of a short 
                  extract, and anyway the bit of music 
                  that we had heard didn't sound all 
                  that bad to me. Nevertheless, 
                  it was quite unlike anything I had 
                  hitherto experienced, which I suppose 
                  makes it fairly "way out", and spurred 
                  by the general scorn, my inherent 
                  bloody-mindedness dictated that I 
                  investigate further. 
                
 
                
As luck would have 
                  it, a combination of relative impecunity 
                  - a perennial problem for a "working 
                  class" record collector - and abject 
                  failure of local record shops to connect 
                  with the source of supply prevented 
                  me from getting hold of a copy of 
                  the record. So, end of story? Well, 
                  almost but, as you might guess, not 
                  quite. Fully four years went by, before 
                  two unrelated events rekindled my 
                  curiosity. The first was an item in 
                  the Bulletin of the (then) 
                  National Federation of Gramophone 
                  Societies, wherein the editor, the 
                  late Bill Bryant, to whom I shall 
                  be eternally grateful, let it slip 
                  that he had actually got hold of several 
                  of those CRI records, including that 
                  particular one. 
                
 
                
A year further down 
                  the line, researching for a projected 
                  Huddersfield Gramophone Society programme 
                  on "Music from the New World", I came 
                  across a reference to a book called 
                  Genesis of a Music. The author’s 
                  name was the same as the composer 
                  of that scorned musical extract. Coincidence? 
                  Not likely: let’s face it, Harry 
                  Partch is not the sort of name 
                  that overburdens the telephone directory. 
                  I checked the index in the Bradford 
                  Library, and to my utter amazement 
                  found that the book was actually on 
                  the shelf! Borrowing it, I found it 
                  a substantial tome of well over 500 
                  fairly large pages, which I read from 
                  cover to cover - twice! What 
                  I found there, though understood only 
                  in part and then with some difficulty, 
                  convinced me that I should make Harry 
                  Partch the centrepiece of my programme, 
                  with the help of the loan of one of 
                  Bill's records. 
                
 
                
By now you have every 
                  right to ask, especially if on one 
                  particular occasion you had dismissed 
                  a fragment of very strange-sounding 
                  music with a summary "What rubbish", 
                  just what it was that "transformed 
                  my attitude to music"? Let me try 
                  my best to explain . . . 
                
 
                
2	Partch's 
                  Achievement 
                
 
                
That lady was in 
                  good company: no less a personage 
                  than Norman Lebrecht has also dismissed 
                  Partch, calling him a "crackpot inventor". 
                  On this occasion at least, good old 
                  Norman is talking right out of the 
                  back of his head. I discovered that 
                  the California-born Harry Partch, 
                  far from being simply a "crackpot 
                  inventor" and composer of "rubbish", 
                  is in fact an archetypal "pioneer", 
                  riding his covered wagon westward 
                  into musical territories to all modern 
                  intents and purposes utterly uncharted. 
                  He turns out to be one of the most 
                  original musicians of this century, 
                  if not in the entire history of the 
                  music of Western Civilisation. 
                
 
                
As a young man, Partch 
                  (1901-74) became increasingly dissatisfied 
                  with the entire "business" of music, 
                  with its widespread emphasis, both 
                  by teachers and authors, on high levels 
                  of instrumental skills and on playing 
                  and composing "technique". That is, 
                  if a work was "polished" in performance 
                  or compositional technique then it 
                  was automatically "good", if a player 
                  was extremely dexterous then he was 
                  ipso facto an "artist", and 
                  if he could play in such a way as 
                  to please the "experts" - whoever 
                  they might be - then he was, equally 
                  ipso facto, a "great artist" [Genesis 
                  of a Music, p4]. 
                
 
                
What seemed to irk 
                  Partch so much was that everyone was 
                  busily fêting the virtuosi and 
                  indulging in strictly ritualised concerts, 
                  but no-one seemed to be giving any 
                  real thought to the intrinsic value 
                  of the materials with which they were 
                  working - and here he meant not just 
                  the basic philosophical attitudes, 
                  but the very organisation of 
                  sounds which distinguishes "music" 
                  from "noise". 
                
 
                
He wasn't over the 
                  moon about music schools and teachers, 
                  either. Music, of all the Arts, seems 
                  to be the only one whose proponents 
                  steadfastly refuse to "demean" themselves 
                  by acquaintance with the science in 
                  their art. Thinking about it, such 
                  is the mystique surrounding Music 
                  as an art that one of the surest ways 
                  of precipitating a fit of apoplexy 
                  in a musician is to suggest that Music 
                  is a branch of mathematics. 
                  Worse, Partch found that the little 
                  "science" that was taught was at best 
                  superficial, often sketchy, and at 
                  worst completely spurious. 
                
 
                
Apparently, what 
                  he found so utterly exasperating was 
                  that Music was presented as something 
                  immutable, even sacrosanct: the 
                  student was fed rules and regulations 
                  by rote, and if he dutifully learned 
                  and practised them he would become 
                  a "good musician". But, it seemed 
                  to be forbidden to question the validity 
                  of the quasi-biblical "rules", or 
                  to enquire into the whys and wherefores 
                  of the structure of the art. The reason? 
                  TRADITION, or, more bluntly, "fossilisation". 
                  We had better and better pianists, 
                  conductors, composers, we increased 
                  the range of our "good" music, but 
                  the tradition itself remained undisturbed 
                  because the ideas and objects at the 
                  heart of the art were not challenged 
                  and investigated, not even by the 
                  supposed "avant-garde". 
                
 
                
So, even in his teens, 
                  he had more or less given up on the 
                  musical system and establishment of 
                  modern Europe. He turned to the public 
                  libraries in a search for material 
                  from which to learn. At the ripe old 
                  age of 21 he came across the key to 
                  his dilemma, a work not of musicology 
                  but of physics: Ellis' translation 
                  of On the Sensations of Tone, 
                  by Helmholtz. This so convinced him 
                  that the traditional system was rotten 
                  in its very foundation - in its implementation 
                  of the concept of "tonality" - that 
                  he made an almost unimaginably bold 
                  decision, one that would freeze the 
                  blood in the veins of most mortals. 
                  Consigning his entire musical output 
                  to date to the tender mercies of a 
                  pot-bellied stove was a gesture both 
                  practical and symbolic: he turned 
                  his back on the current musical tradition 
                  and, working from first principles, 
                  set out to create an entire Music 
                  of his own from scratch. 
                
 
                
3	The Tonal 
                  System 
                
 
                
The first thing Partch 
                  needed to determine was the tonal 
                  system in which his music would operate. 
                  To be true to his principles, he could 
                  not just throw out the "traditional" 
                  one and concoct another one willy-nilly. 
                  To succeed, he had to be committed 
                  to justifying, scientifically and 
                  practically, whatever he devised. 
                  This is such a fundamental step that 
                  it bears reviewing in some detail. 
                  Fortunately, it is also a fascinating 
                  and revealing - though (be warned!) 
                  difficult - subject. It might help 
                  to be aware that what follows is ultimately 
                  derivable, believe it or not, from 
                  the simple physics of a vibrating 
                  string such as we are all taught at 
                  school. True, this same basis is often 
                  used in conventional music theory, 
                  but as we shall see its application 
                  is fundamentally flawed. 
                
 
                
Ring Out the New 
                  . . . 
                
 
                
As we all know, the 
                  scale now used universally in all 
                  music of the Western European tradition 
                  - be it "classical", "popular", "jazz", 
                  or whatever - is that playable on 
                  a piano keyboard. The "octave" is 
                  divided into 12 equal intervals, or 
                  "semitones", appropriate selections 
                  of eight of which provide all the 
                  "keys": 12 "major" and 12 "minor". 
                  And are we not taught in school of 
                  the birth of this intonational system 
                  as if it were the Messiah of some 
                  religion (with J S Bach in the role 
                  of John the Baptist)? If not, we may 
                  as well be, for all that we learn 
                  of what it really is and how 
                  it really works. 
                
 
                
Most "traditional" 
                  musicians would probably recoil in 
                  horror if told that each degree (note) 
                  of the scale is determined exactly 
                  by multiplying the frequency of the 
                  previous degree by a factor of 21/12 
                  - that the Holy Musical Scale should 
                  be derivable by mere common mathematics! 
                  But worse, much worse, is to come. 
                  The ONLY truly consonant interval 
                  of this hallowed system, 12-tone 
                  equal temperament (ET), is the 
                  octave, that is the interval 
                  between two degrees such as C and 
                  C'. ALL, bar none, of the so-called 
                  major intervals and chords (such as 
                  C-E-G-C), are dissonant! ALL, bar 
                  none, of the other chords and intervals 
                  are more dissonant! 
                
 
                
We will come to the 
                  meanings of "consonant" and "dissonant" 
                  in a moment. I recall a TV documentary 
                  in which no less a figure than Olivier 
                  Messiaen explained his characteristic 
                  chord structures. He played a sequence 
                  of notes on a piano and proclaimed, 
                  "There! I have played all the harmonics." 
                  With due respect, he was wrong on 
                  not one but two counts. Firstly and 
                  perhaps a little pedantically, he 
                  had played only a dozen or so notes, 
                  which is rather too few to constitute 
                  "all the harmonics". Secondly and 
                  rather more crucially, he had played 
                  none of the harmonics, other 
                  than the octaves of his chosen fundamental. 
                
 
                
Galileo penned a 
                  perceptive and penetrating observation: 
                
 
                
 
                  "Agreeable consonances 
                    are pairs of tones which strike 
                    the ear with a certain regularity; 
                    this regularity consists in the 
                    fact that the pulses delivered by 
                    the two tones, in the same interval 
                    of time, shall be commensurable 
                    in number, so as not to keep the 
                    eardrum in perpetual torment, bending 
                    in two different directions in order 
                    to yield to the ever-discordant 
                    impulses." 
                  
 
                
                This holds the key 
                  to "consonance" and "dissonance". 
                  What it means is that, at regularly 
                  occurring instants, the two vibrations 
                  will be in step, and, as any mathematician 
                  or physicist will tell you, this is 
                  possible only if the frequencies 
                  of the two tones are in whole-number 
                  proportions. Moreover it follows, 
                  partly from Galileo's statement, that 
                  the degree of consonance of an interval 
                  decreases from 1/1 (unison, where 
                  the frequencies are equal) as the 
                  size of the whole numbers involved 
                  increases. This is because the tones 
                  are in step less often. With big enough 
                  numbers the interval eventually approaches 
                  "complete" dissonance, as the tones 
                  are in step so rarely that the ear 
                  can no longer perceive the regularity 
                  of the pattern. 
                
 
                
The limit of this 
                  progression from absolute consonance 
                  to absolute dissonance comes when 
                  the numbers become infinitely large, 
                  in that remote realm where the rational 
                  number locks horns with its irrational 
                  counterpart. The "irrational number" 
                  is a thoroughly nasty beast: it cannot 
                  be exactly represented by the ratio 
                  of two whole numbers or, equivalently, 
                  requires an infinite sequence of non-recurring 
                  decimal digits (B 
                  is the classic example). 
                
 
                
Since the adjacent 
                  degrees of ET, the piano scale, are 
                  by definition related by factors of 
                  21/12, and 21/12 
                  is an irrational number, we cannot 
                  escape the conclusion that no two 
                  ET tones (other than the unison and 
                  octaves) can form a consonant interval. 
                  The intervals in an octave are 1 (i.e. 
                  20), 21/12, 
                  21/6, 21/4, 
                  21/3, 25/12, 
                  21/2, 27/12, 
                  22/3, 23/4, 
                  25/6, 211/12, 
                  2 (i.e. 21), all of which, 
                  except 1 and 2, are irrational. 
                
 
                
I sometimes wonder 
                  just how such a temperament ever gained 
                  its monopoly in our music. Up until 
                  around the time of Handel, all music 
                  was based on Just Intonation (JI), 
                  which we shall consider in a moment. 
                  It seemed that there was some difficulty 
                  in developing keyboards (lately gaining 
                  in popularity) which could cope effectively 
                  with JI. So, with a zeal more characteristic 
                  of late twentieth century business 
                  corporations, Keyboards Inc. set 
                  about "effective management" 
                  of its "customer perceptions". 
                
 
                
Handel, bless his 
                  cotton socks, resisted manfully, maintaining 
                  for some time a keyboard with additional 
                  keys which did support JI intervals. 
                  Ironically, the keyboard lobby’s victory 
                  actually made life harder for players 
                  of other instruments. In particular, 
                  brass players (trombonists apart!) 
                  now had to "force" their intonation 
                  to fit, and it seems nobody has ever 
                  made any serious effort to remedy 
                  this: to this day, brass pitching 
                  is perforce "approximate". The key 
                  point, though, and the one that impressed 
                  Harry Partch, is that the crucial 
                  purity of musical intonation 
                  was sacrificed on the altar of business 
                  convenience - a close parallel to 
                  his own experiences. Exactly why this 
                  is crucial is something that we will 
                  tackle shortly. 
                
 
                
. . . and Ring 
                  In the Old 
                
 
                
All musical intervals 
                  are based on ratios: two tones 
                  are related by the ratio of their 
                  frequencies. There are natural laws 
                  relating to vibrating strings. A string, 
                  stretched between two fixed points, 
                  will resonate in only certain modes. 
                  These correspond to divisions of its 
                  length into integral numbers of half-wavelengths. 
                  The same is true, though less visibly, 
                  of the vibrating columns of air in 
                  wind instruments, and in a more complex 
                  way in two dimensional bodies like 
                  drumskins or three-dimensional ones 
                  such as our old friends, the "coconut 
                  shells"! 
                
 
                
The "harmonic series" 
                  of a vibrating string is often used, 
                  all too briefly, as a starting point 
                  for traditional teaching of music 
                  theory, just before turning to the 
                  piano and demonstrating its application. 
                  Teachers seem to be either ignorant 
                  of the fact that the ET scale of the 
                  piano, based as it is on paradoxical-sounding 
                  irrational ratios, does not actually 
                  correspond at all, or at best dismiss 
                  the differences as "insignificant" 
                  - regardless of the fact that similar 
                  "insignificant" differences in the 
                  tuning of instruments in an ensemble 
                  would sound ghastly. 
                
 
                
The "natural" JI 
                  intervals are based on ratios of small, 
                  whole numbers, corresponding exactly 
                  to the harmonics of that vibrating 
                  string. Unison is 1/1, an "octave" 
                  is 2/1, and other common ones are 
                  3/2 and 5/4, so that for example a 
                  3/2 implies 
                
              
              
 
                
                  		higher tone = 3 x (lower 
                    tone)/2 
                
              
               
               
                
These conform to 
                  Galileo's definition of "agreeable 
                  consonances": for a 5/4 the vibrations 
                  are exactly in step once every 5 cycles 
                  of the higher tone, corresponding 
                  exactly to once every 4 cycles of 
                  the lower. Any such ratio can be "reduced" 
                  into the range 1 to 2 by a process 
                  of doubling or halving either of the 
                  numbers. For example 7/3, which is 
                  bigger than 2, becomes 7/6, which 
                  is between 1 and 2, by doubling the 
                  lower number. This is nothing more 
                  than our common practise of "octave 
                  transposition". 
                
 
                
It also highlights 
                  the importance of the 2/1 interval. 
                  Long history and much experimentation 
                  have shown that the human ear recognises 
                  some tones as distinct, and 
                  others as distinctly not. The 
                  ear will recognise the difference 
                  in pitch of the two tones of a 2/1 
                  interval, but will not afford them 
                  a different identity, broadly 
                  because every time the lower tone's 
                  vibration is at a peak or trough, 
                  so is the higher tone's. However, 
                  the reason for this is not too important 
                  here: it is in any case a physiological 
                  axiom, true of any scale - JI, ET, 
                  Mean Tone, or whatever. The intervals 
                  5/2 and 5/4 have the same identity, 
                  that is, both represent the same degree 
                  of a JI scale, just as A and A' both 
                  have the identity A in ET. In JI, 
                  reducing a ratio to between 1 and 
                  2 is equivalent to (say) referring 
                  to "G" without saying which octave 
                  it's in. 
                
 
                
The preference shown 
                  by the human ear - and that of a dog, 
                  a cat, or a bat, for all we can tell 
                  - for JI intervals over ET ones is 
                  also a physiological axiom, notwithstanding 
                  both biophysical considerations and 
                  that this is exactly what Galileo 
                  was driving at. Partch used to stage 
                  experiments during lectures, playing 
                  corresponding chords in both systems 
                  to the "innocent ears" of his audience, 
                  who would then be invited to vote 
                  for which they preferred. Always, 
                  and overwhelmingly, the JI chords 
                  were preferred to the ET equivalents. 
                
 
                
The reason for this 
                  is illustrated in Fig. 1, a 
                  comparison of the waveforms for an 
                  ET major triad (like C-E-G) and the 
                  equivalent JI triad (1/1-4/3-3/2). 
                  The strongest peaks correspond to 
                  the frequency of the tonic. You can 
                  clearly see that the JI curve replicates 
                  exactly in each cycle between 
                  pairs of these peaks - in accord with 
                  Galileo's dictum. The ET curve sets 
                  out in step with the JI, but soon 
                  diverges and, as mentioned earlier, 
                  is never repeated exactly, 
                  but varies progressively from cycle 
                  to cycle, i.e. it is not consonant! 
              
              
 
              
 
              
 
                Evidence abounds 
                  for the ear's inherent preference 
                  for JI. Ensembles comprising only 
                  instruments of continuously variable 
                  pitch (such as violin family, voices, 
                  trombones) in performance invariably 
                  revert to JI, offering one tempting 
                  reason why an a cappella choir, 
                  for example, sounds so extraordinarily 
                  beautiful. Then again, have you ever 
                  wondered why the ear should enjoy 
                  a smidgen of judicious vibrato, if 
                  not to blur the dissonance inherent 
                  in the ET scale? In a justly-intoned 
                  performance, vibrato would actually 
                  be detrimental to the sound, unless, 
                  that is, it was being used to mask 
                  poor intonation! More mundanely, I 
                  have heard string players grumble 
                  about how they have to play their 
                  notes "a bit wrong" to fit in with 
                  a piano, yet very rarely seem inclined 
                  to wonder why! 
                
 
                
Musical Scales 
                
 
                
A scale is a sequence 
                  of degrees, identities connecting 
                  1/1 to 2/1. But what degrees, and 
                  related by what intervals, actually 
                  constitute a scale? Without any rules 
                  to define the relationships, literally 
                  "anything goes" - and possibly, right 
                  now, a "glimpse of stocking" might 
                  seem a little short of "something 
                  shocking"? Why, for example, is our 
                  ET fixed at only 12 identities? There 
                  are 12 simply because the interval 
                  is 21/12. There is no reason 
                  why there should not be 24, with a 
                  fixed interval between successive 
                  identities of 21/24. Of 
                  course, one or two composers in the 
                  Twentieth Century have dabbled with 
                  this "quarter-tone" scale. But why 
                  not 19, or 3759, or even 42 (which 
                  might appeal to aficionados of The 
                  Hitch-hiker’s Guide to the Galaxy). 
                  Observing that the intervals are called 
                  "semitones" leads nowhere either: 
                  a "whole tone" is an equally arbitrary 
                  21/6! The only reason for 
                  12 would seem to be that this most 
                  closely approximated the JI scale 
                  current at the time that the ET scale 
                  was invented. 
                JI intervals are 
                  ratios of "small, whole numbers". 
                  The question is: which numbers? 
                  Mathematically, there is a sequence 
                  of special numbers: 1, 2, 3, 5, 7, 
                  11, 13, ... These are the prime 
                  numbers, numbers which are exactly 
                  divisible only by themselves or 1. 
                  Prime numbers are crucial in JI largely 
                  because of this property of irreducibility. 
                  They prescribe sets of whole-number 
                  ratios. The "ratios of N", 
                  where N is a prime number, define 
                  potential JI scales. Take 3, for example. 
                  The ratios of 3 are 
                1/1 (unity), 4/3, 
                  3/2, 2/1
                 These are all the 
                  ratios which are possible, using prime 
                  numbers no greater than 3. They have 
                  been transposed into the range 1 to 
                  2: the ratio 4/3 is musically identical 
                  to 2/3 (as 4 is a doubling of 2). 
                  Seeing as ratios of 1 (1/1 alone, 
                  poor Johnny One-Note) and 2 (1/1, 
                  2/1 only, Johnny and his boring sister 
                  Joan) provided only a single identity, 
                  and consequently virtually zero musical 
                  potential, it comes as no surprise 
                  that the ratios of 3 formed the basis 
                  of the most primitive scales. After 
                  the 1/1 (unison or unity) and 2/1 
                  ("octave"), 4/3 and 3/2 
                  are the most powerfully consonant 
                  intervals, both alive - though not 
                  entirely well - in ET's "perfect 
                  fourth" and "perfect fifth". 
                  Without recourse to matters celestial 
                  or divine, the meaning of "perfect" 
                  is suddenly crystal clear! 
                The ratios of 5 are 
                
                1/1, 6/5, 5/4, 
                  4/3, 3/2, 8/5, 5/3, 
                  2/1
                again, transposed 
                  into the range 1 to 2. Notice that 
                  the set of ratios of 3 (shown in 
                  bold) necessarily appears as a 
                  subset. As time progressed, more of 
                  these intervals became recognised 
                  as "consonant", in the sense 
                  that they became "acceptable" 
                  in musical terms. The sequence is 
                  symmetrical, the intervals between 
                  the degrees widening from the centre 
                  outwards. Such gaps were closed, to 
                  provide a more melodious spacing, 
                  by the entirely legitimate use of 
                  multiple number ratios, that 
                  is, ratios formed by combining simple 
                  ratios of 5, e.g. 16/15, 9/8. These 
                  are nothing more than "compound 
                  intervals": a new interval results 
                  from the adding of two intervals, 
                  and to add two intervals you just 
                  multiply their ratios. Thus 4/3 x 
                  8/5 = 32/15, which is identical with 
                  16/15, and 3/2 x 3/2 = 9/4, identical 
                  with 9/8. The ratios of 5, with associated 
                  compound intervals, form the basis 
                  of the JI scale which was "converted" 
                  to produce 12-tone ET. 
                Table 1 shows how 
                  the "conversion" might have 
                  been made (I say "might", 
                  because I have derived this representation 
                  myself, from first principles). The 
                  ratios of 5 identities are shown in 
                  bold, and all the multiple 
                  number ratios are also shown. Two 
                  (10/9 and 9/5) are shaded because 
                  these are not represented in ET (you 
                  win some, you lose some - these are 
                  where the pairs of JI alternatives 
                  are relatively close - another example 
                  of operational convenience?). The 
                  places where pairs of JI degrees were 
                  reduced onto a single, approximate 
                  ET degree can be seen clearly, as 
                  can the familiar resulting pattern 
                  of "white" and "black" 
                  notes.
                 Note how each "black" 
                  note has two possible corresponding 
                  JI identities, one a bit lower and 
                  the other a bit higher in frequency: 
                  Handel's "JI keyboard" would 
                  have retained these as distinct keys. 
                  That the scale starts on D is due 
                  (probably, though I am not going to 
                  go into that here, as it isn't really 
                  relevant) to the shift in concert 
                  pitch - the JI scale would originally 
                  have been transposed onto the key 
                  of C. Some of the approximations, 
                  as shown by the differences, are disturbingly 
                  high. 
                In JI it is obviously 
                  possible to use ratios of 7, 11 and 
                  so on, and derive musical scales with 
                  ever more identities to the "octave", 
                  limited in practical terms only 
                  by the ear's ability to distinguish 
                  them. Of course, the higher the 
                  numbers employed, the greater become 
                  the degrees of comparative dissonance, 
                  with consequent widening of the scale's 
                  expressive potential. 
                There was at one 
                  time a controversy over the "legality" 
                  of the chord of the dominant seventh, 
                  which related to an implied extension 
                  beyond the 5 limit enshrined in ET. 
                  Significantly, the introduction of 
                  ET effectively closed the door on 
                  the development of the expressive 
                  potential of musical scales. Over 
                  several hundred years, we had moved 
                  from 3-limit ratios to full use of 
                  5-limit ratios. There is no reason 
                  to suppose that this development would 
                  have stopped there, had not the imposition 
                  of ET "crystallised" the 
                  5-limit.
                
                
                Part 
                  2 Part 
                  3