Although it would be nice to trace back the idea of using noise as an element in music to the futurist Luigi Russolo's manifesto, The Art of Noises, published in 1913 , there are earlier ancestors. The painter Russolo's manifesto was itself inspired by the writings of futurist composer Balilla Pratella, whose Technical Manifesto of Futurist Music (1911) includes the passage: "[Music] must represent the spirit of crowds, of great industrial complexes, of trains, of ocean liners, of battle fleets, of automobiles and airplanes. It must add to the great central themes of the musical poem the domain of the machine and the victorious realm of electricity" . Sadly, Pratella's own music was much more conventional than his aims might suggest.
In the few years before these, better known classical composers were already struggling out of the straitjacket their musical tradition had placed them in. Ferruccio Busoni's 1907 Sketch for a New Aesthetic of Music asked: "In what direction shall the next step lead? To abstract sound, to unhampered technique, to unlimited tonal material" . (Busoni also praised Thaddeus Cahill's trautonium, recognising early on the potential of electronic music). The composer surely didn't realise quite what he was prophesying; the next step he imagined might appear to be the one taken by Schoenberg, Ives and Cowell, who between 1907 and 1919 worked through increasingly atonal approaches to music that rapidly increased in dissonance and (in Cowell's case) in their exploration of new uses for old instruments. However, Busoni's words could just as easily be taken to imply the diverse musics of artists like Asmus Tietchens, or Merzbow. When the classical composers first resolved to let noise enter their music, they didn't realise quite what it was that they unleashed.
One of the aims of the Futurists was to oppose the classicism and romanticism that they felt dominated artistic expression at the time. Both art and music, the Futurists thought, were concerned with nostalgia, with the depiction of mythical past idylls. In opposition to this, they demanded that their art reflect dynamism rather than stillness, the future rather than the past, and the grinding noise of the machine rather than the pure, beautiful sounds that Romanticism produced.
Russolo's instruments have long since been destroyed, and his music can now only be heard in rare reconstructions, but his importance lies more in his ideas than in the tiny influence that he actually had on other composers and musicians. The Art of Noises is notable because its aesthetic ideas comprehensively predate almost all the musical movements that eventually produced industrial music. Pierre Schaeffer and Pierre Henry paid tribute to Russolo when they created musique concrète, but they had little idea what his music actually sounded like: there is only one surviving recording of his instruments, and it wasn't unearthed until 1957. 
If Busoni had taken one faltering step towards musical freedom, The Art of Noises took a giant leap. According to Russolo: "In the 19th century, with the invention of machines, Noise was born. Today, Noise is triumphant and reigns sovereign over the sensibility of men ... Musical sound is too limited in its variety of timbres ... We must break out of this limited circle of sounds and conquer the infinite variety of noise-sounds ... Noise, arriving confused and irregular from the irregular confusion of life, is never revealed to us entirely and always holds innumerable surprises." 
Not only had Russolo set out ideas that would resurface in previously unimaginable areas of twentieth century music, but in his words about the "confusion" inherent in noise, he anticipated an idea of central importance to any aesthetic theory of noise music. Despite this, Russolo's manifesto also contains some highly conservative ideas, most obviously his proposal that noises be selected according to their pitch. I can't imagine how he intended to assign a pitch to noises like "explosions" and "death rattles", both of which he planned to create.
Russolo created many noise instruments, such as the "Whistler", the "Burster" and the "Croaker", each of which had a limited ability to produce one type of noise, and according to his own accounts, early performances using them tended to degenerate in near riots, in much the same way as nights at the Cabaret Voltaire or the premiere of Stravinsky's The Rites of Spring did. More recently of course, the response to performances by groups like Throbbing Gristle, Cabaret Voltaire and Whitehouse has been similar. It's easy to exaggerate Russolo's similarities to the later industrial musicians; after all, for every occasional rumpus when Genesis P-Orridge took up his mike, there were ten at punk gigs in the late seventies.
None of the people involved in industrial music seems to have thought much in a theoretical way about their use of noise elements, which is in keeping with the groups' general ignorance of musical matters. Perhaps the most interesting study of the topic is Jacques Attali's Noise - The Political Economy of Music . Attali wrote that: "Listening to music is listening to all noise, realising that its appropriation and control is a reflection of power, that it is essentially political ... The theorists of totalitarianism have all explained that it is necessary to ban subversive noise because it betokens demands for cultural autonomy, support for differences and marginality: a concern for maintaining tonalism, the primacy of melody, a distrust of new languages, codes or instruments, a refusal of the abnormal - these characteristics are common to all regimes of that nature". Attali's view gives the lie to those who think that music and politics don't mix; I agree with his view that what is political about music occurs at a more basic level than that of lyrics or presentation.
Attali presents the history of music as a mirror of the history of capitalism, dividing that history into three stages (broadly, of "primitive" ritual music, scored music and recorded music ). He points out correspondences between the rise of scored music and the rise of technocratic, bourgeois society, and also between the growth in recorded music and the transformation into a more classless, commodity-centred society. Attali presents a blueprint for a fourth stage in musical history, which he expects to prefigure wider social and economic transformations. A key element in this fourth stage (which Attali confusingly terms composition) is that musicians will again begin to create music not just as a commodity or text for exchange, but for their immediate personal pleasure (this has of course been an important trend in recent decades). Another key element is that the new music will operate outside the mainstream musical industry, but the most important component is that the new music will rediscover noise and violence as crucial for its expression (he cites John Cage and free jazz as prototypes of this new musical stage).
One musicologist suggested that punk or new wave was the first major sign of this musical paradigm shift. "Many of the original groups began as garage bands formed by people not educated as musicians who intended to defy noisily the slickly marketed 'nonsense' of commercial rock. The music is often aggressively simple syntactically, but at its best it conveys most effectively the raw energy of its social and musical protest. It bristles with genuine sonic noise (most of it maintains a decibel level physically painful to the uninitiated) ..."  As is usual with academic commentators, there is a marked tendency not to be aware of anything outside a narrowly defined frame of reference, and it's tempting to suggest that much of industrial music fits this description better than the punk rock that inspired it. However, there are musical areas which fit Attali's ideas more closely (particularly free improv music), and industrial music should be seen as only one strand amongst many attempts to break free of this century's more reactionary musical trends.
Clearly then, industrial music's attempts to smash received musical values and rules, to tear down conventional notions of taste and to seek pleasure in brutal ugliness, were part of an important tendency in modern music, a reaction against the political control that most music mirrored, both in its overall aesthetic and in its means of production. John Cage's understanding of the same ideas led him to seek to minimise his own control over the music he made; Brian Eno's control over his sound is much tighter, but he shows equal political radicalism in attempting to create a music that allows many different levels of attention for the listener, that presents a surface for the listener to investigate rather than a (party) line for the listener to follow. In free improv of the sorts pioneered by Evan Parker or AMM, the political message lies in how the group organises itself to create sound, rejecting one individual's programmatic vision in favour of sound that is spontaneous, cooperative, and above all, playful.
As an aside, Throbbing Gristle may not be the first name that improv historians think of, but more than most rock bands, they relied heavily on an improvising approach. The recordings of their dozens of live performances are valued by fans for this very reason. According to T.G.'s Peter Christopherson: "Pieces were created more or less spontaneously, without any rehearsal or preparation other than Chris' privately made rhythm tracks and a general discussion about possible topics for a new lyric which Gen would use as inspiration for the lyric ... We had little idea of what was going to happen in any performance or recording session, and each of us contributed our share entirely on the basis of what was going on at that very moment."  Given the personalities present in T.G., you could be forgiven for thinking that Christopherson is idealising what actually happened, but it's clear that the level of improvisation in T.G. and other groups went far beyond what happens in song-fixated rock groups.
For a slightly less politicised idea of the importance of the noise element in industrial music, I find some inspiration in the writing of rock critic Simon Reynolds (for his part, he draws heavily on the ideas of post-modernist philosophers like Roland Barthes and Jean Baudrillard). Reynolds' view of noise relies heavily on its power to disrupt and intoxicate: "Noise then, occurs when language breaks down. Noise is a wordless state in which the very constitution of our selves is in jeopardy. The pleasure of noise lies in the fact that the obliteration of meaning and identity is ecstasy." 
Before industrial music there were certainly strong noise elements in music, but rarely in the way that there were afterwards. Russolo's noise instruments, for all their potency in their day, sound nowadays like mere sound-effects machines, and strangely subdued ones at that. Edgar Varèse, lauded by John Cage as the "father of noise" in twentieth century music composed much that was radical by conventional classical musical standards, but little that matches the noise music of recent years. Iannis Xenakis, like Krysztof Penderecki and Gyorgy Ligeti, explored microtonality to create terrifying musical effects that are still powerful today, but the textures they created could in no way be considered "noise".
Of all the avant-gardists of the first 60 years of this century, only John Cage can really take credit for producing music that even today's Gerogerigegege fans might find hard to listen to. As well as his percussion-oriented pieces for prepared piano, where the irregularity of the objects placed between the piano strings ensured a sound that was sometimes cacophonous, it was his live electronics pieces that delivered the healthiest dose of raw, obnoxious noise. Cage's insistence on chance procedures (for example, while some performers produce the sounds, others operate the volume controls, all in accordance with randomly-determined timings) ensured that his music would be unpredictable and chaotic. In a piece like Cartridge Music where much of the sound is produced by rubbing a record player's stylus cartridge against various objects and surfaces, the sound itself takes on a raucous, violent feel, with a shocking, harsh texture that some industrial groups never matched.
In 1937, Cage had written: "Wherever we are, what we hear is mostly noise ... Whether the sound of a truck at 50mph, rain, or static between radio stations, we find noise fascinating ... [I intend] to capture and control these sounds, to use them, not as sound effects, but as musical instruments" . Cage cited Russolo's The Art of Noises and Henry Cowell's New Musical Resources as important precursors, and his comments on the use of everyday noises as the constituents of music predate musique concrete. Pieces like his Third Construction, for a variety of traditional and "found" percussion instruments, predate industrial music's love of metal percussion by several decades. Unlike the futurists, however, Cage was not interested in simply reflecting modern technology in his music, but in gaining access the whole field of sound.
Dig hard enough and you'll find other examples, as after all, white noise was as rapid a byproduct of new technology as pure tones were. So it is that even in 1973, a composer like John Oswald could create noise music almost indistinguishable from the post-industrial musicians, using an evolving swarm of electronically-generated white noise.
Outside the "classical" world, however, there was a far more important source of inspiration. With the release of the Velvet Underground's first record in 1967, rock music had reached a turning point. For not only did the V.U. incorporate elements of the avant-garde tradition into their music (mainly thanks to John Cale's education in drone courtesy of La Monte Young ), but they combined this with one of the most alienated, hostile attitudes rock had so far developed. If their art background (courtesy of Andy Warhol) and interest in sexual deviance (Venus in Furs, Sister Ray) had echoes amongst the first wave of industrial groups, perhaps it's no surprise.
Singer-songwriter Lou Reed's post-Velvets career is mostly of no relevance whatsoever to industrial music, but his 1975 double-album, Metal Machine Music, remains an awesome landmark. Most of his fans fell for the story that this was a "contractual obligation" record, a successful attempt to piss off his label, RCA. Very few people took it seriously: it's been described as "unlistenable noise" by most writers who otherwise enjoy Reed's output. At the time, Reed's own comments were ambiguous, sometimes adding fire to the stories about arguments with his label, but at other times he stated that the album was intended as a serious composition. With hindsight, it's easy to see Metal Machine Music as the honoured ancestor of post-industrial noise, four sides of churning, screeching feedback that never let up for a moment. Compared to some of today's noise-makers it seems positively polite, and the interest in repetition and drone frequencies make clear that Reed had paid attention to his band-mate Cale's influences. Whether or not many industrial musicians had heard the record or not must be doubtful, but it still sounds refreshing today, even in the light of two decades of industrial and no-wave aural abuse.
The development of further music that employed noise not just to distract from more conventional textures, or as a byproduct of conventional rock guitar aggression, had to wait until after the industrial music revolution, but it owed as much to Metal Machine Music as it did to the proof by people like Cage and the improv group AMM that a musical experience could be created from even the most unlikely materials. Many musicians have experimented with extreme noise; as well as artists like Non, Controlled Bleeding or the New Blockaders, Japan is recognised as home to much of the most powerful variety, thanks to groups like Merzbow, the Gerogerigegege, the Hanatarash and others. The motives of the musicians vary; some, like bungee jumpers, are just looking for an intense experience; others may have genuine loathing that they want to express; others just find a child-like fun in noise-making.
Simon Reynolds recognises the symptoms that ensure noise music often goes hand in hand with other extreme subject matter: "The subliminal message of most music is that the universe is essentially benign, that if there is sadness or tragedy, this is resolved at the level of some higher harmony. Noise troubles this world-view. This is why noise groups invariably deal with subject matter that is anti-humanist - extremes of abjection, obsession, trauma, atrocity, possession ..."
Despite his lucid attempt to describe noise's revolutionary potential, capable not of destroying any external enemy but of demolishing internal mental power structures, Reynolds acknowledges that theory and noise are at odds. Noise resents being asked to have meaning, it refuses simple explanations and it is at its best when it just exists; deep and meaningless.
As a response to society noise is the apotheosis of many of industrial music's aims. Throbbing Gristle and Cabaret Voltaire may have mirrored the faceless anonymity of post-industrial society in their drab, grey-stained rhythms but the noise elements in their music also reflected an anger, recognising their own alienation and loathing it deeply. In a society where people cross the road at the merest hint of violence, not out of fear (because television hyper-reality desensitises that emotion), but out of disinclination to be involved, where the powers that determine our freedom of action seem increasingly less concrete, less amenable to opposition, the sense of meaning is collapsing, and the appropriate musical response is obvious; the silent scream, brutal, oblivious burnout.
The concern of earlier avant-gardists was simply to search for freedom from the will-to-power that Jacques Attali sees in all composed music; the concern of industrial music was to find an adequate response to a post-collapse society, a society that had yet to understand quite how empty its core had become. With industrial music, the power set in motion by Russolo had finally begun to realise some of its true potential.
Many thanks are due to Marc Gascoigne, without whom this article would be considerably poorer.