Consider the modern record producer. Sitting in a cosy wood-and-glass den, thinking about a second synth line, perhaps, or exhorting a performance from a nervous singer. But what about the people who made the producer's job possible?

Sometimes the modern producer might wonder about the people who invented the tools of the trade, but the indebtedness goes much deeper than that. Every technique, every sound committed to tape, is owed to the pioneers of record production: the people who invented the musical and technical language which the producer of today borrows for his or her own expression.

The story of rock music is the story of records — in more ways than one. Records started as a mirror of the music, but soon became a catalyst, spreading ideas and fostering both innovation and imitation.

The first records were made by conductors, arrangers, session supervisors, and engineers. Somewhere along the line that band of specialists jelled into one multitalented individual, and the record producer was born.

The record producer is a new type of artist, more like the film director than anyone else perhaps, who forges a personal style while contributing a catalogue of typical devices for rivals and successors to borrow. It is the growth of this new type of artist which John Morrish will be examining in 'Heroes' over the coming months.

Every story has a beginning, and ours starts with a man called Sam Phillips in Memphis, Tennessee, in the early 1950s. Sam was a former radio engineer and disc jockey with a small studio and a wild dream of making a million dollars by finding a white man "with the Negro sound and the Negro feel".

That's an unusual ambition in the South at that date, because theirs was a rigorously segregated society, in which black records, black radio stations and black DJs peered across the racial fence at their white equivalents.

What makes this cultural schizophrenia so strange is that both sides shared a common heritage of material poverty and fundamentalist religion. Southern Christianity spoke both of ever-present damnation (reflected in both the blues and country music) and of the near certainty of salvation for the true believer, provoking a chilling arrogance. The music of the Southern churches, both black and white, rings through all the musics of the era.

And what musics they were. Jump blues, country blues, jazz, hillbilly, western swing, cajun, gospel and so on, they owed their separate existence to the curse of social isolation. People in these communities did not travel, and they had no television bringing in "big-city" culture.

The atmosphere was like the primal soup of evolutionary theory. Like new organisms, new musical hybrids would be thrown up and would thrive or fade away. A hillbilly-cajun merger never quite took off, but the hillbillies were singing the blues for years before anyone really noticed.

The spoon stirring this primal soup was radio. Because the ether knows no apartheid. Maybe your mother won't let you go down on Beale Street and mingle with the blacks, but she can't stop you listening to the radio, can she? So much for evolution. It's a useful theory, but it underestimates the part played by individuals.

Sam Phillips had been brought up on a plantation and never lost the taste for black music, even when he was recording slick white jazz as a radio engineer. As a disc jockey, he noticed that all the black artists were heading north to record, so decided to set up a studio in Memphis doing everything from weddings and rotary meetings to the latest blues sides.

His label, Sun, came slightly later, and specialised at first in the blues. All this was new. It wasn't very many years since all black music was recorded literally in the field, with touring recordists taking their wire recorders round the village halls of the south before going back north to issue the discs for scholars and collectors. But the black market had expanded rapidly since the war, and there were fortunes to be made. Phillips had modest hits — but his dream was not modest.

In 1954, with his black stars all gone north to Chicago, Sam had the chance to look seriously for his "white Negro". A handful of country acts recorded for him, and some edged toward the musical fusion that was rockabilly. But the voice was missing.

And then it arrived. Loping through the door, clutching a guitar, came Elvis Aaron Presley. Elvis wanted to make a demo of two Inkspots' songs. He did the same later in the year. And in the end Sam called him in to try out on a song by an unknown black balladeer. It was a disaster. What else can you do? asked Sam, and Elvis gave him an entirely unwanted rundown of the hits of Dean Martin. Even at this stage he had not the slightest grain of taste.

But Sam must have liked something about Elvis's chameleon-like vocal style, because he fixed him up with two musicians, Scotty Moore and Bill Black, who were to stay with him through the great years of his career.

Forget the sad end of his life and imagine the Elvis of July 1954, young, a little arrogant, and very, very hungry. Between the two of them, Sam and Elvis were ready to change the whole course of western music, though Sam didn't know it yet and Elvis probably never would.

Sam's studio is the third hero of the story, a model of economical elegance. A rectangular box, 30ft x 18ft, it had a "dog-leg" crooked wall to break any nasty standing waves and a treated acoustic ceiling. It sounds less dead than a modern studio, more like a living room. In the tiny control room sat two Ampex mono tape machines (one used for echo), and a five-into-one desk. In the studio itself there were a maximum of eight microphones, but no baffles. The leakage between instruments was all part of the sound.

Ah yes, the sound. The Sun Sound started with the very first blues sides. Simplicity was the key to match the basic equipment and the realities of the market. Record pressing quality was so poor that the skilful producer concentrated on getting a good bass sound. The string basses of the day were miked up close then slapped hard with a drum stick when Sam wanted a biting bottom end. Guitar amplifiers were invariably tiny and bright-sounding with a tendency to distort when driven hard. It all went down on tape.

Sam's method was simply to get them in the room and let them get on with it through hours of rehearsal before he ran the tape. Then, there were no overdubs, no remixes, no edits. Sam didn't care about technical brilliance in the playing, he wanted 'feel', and he usually got it.

The only effect available to Sam was echo, and it is echo that has made Sun's name. What he did was to set up a second microphone for the vocalist and feed that signal through the second tape machine to delay it before adding it back in. By varying the speed of the recorder and the size of the tape-loop on it he could get smooth reverberation, or a series of "flutter-echoes" or, most often, a hard repeat called "slapback".

In Sam's hands that echo became the keynote motif of rock 'n' roll. It was, and still is, an instant shorthand for any producer who wants to make his music more "rocky", from Dave Edmunds to the Stray Cats, and even Billy Joel or Elton John. Sam kept his precious echo for his black artists only, until Elvis came along. Presley's innovation came by accident, during a break in a fruitless session devoted to the dreary ballad "I Love You Because". He picked up his guitar and belted into "That's All Right Mama", a thumping blues by Arthur "Big Boy" Crudup, someone Elvis had heard on black radio.

The tiny band joined in behind him and a revolution was born, though only Sam realised what was going on. He came rushing out of the box and made them do it again, this time with the tape running. It worked again. The first of an astonishing series of performances was on tape.

Too many words have been wasted trying to describe the energy, the freshness, the wit, and the lasting charm of these performances. If you have never heard them they may sound as strange and marvellous to you as they did to Sam Phillips.

For the other side of the record they did the opposite to what they had done with "That's All Right" by taking a white country song, "Blue Moon of Kentucky", and giving it a black treatment. Sam cut his acetate dubs. It must have occurred to him that he had his dream. Elvis didn't only sing like a Negro, he sang with the same kind of feeling and his voice expressed the same kind of concerns. But was it saleable?

Sam now had to try and sell America's first racially-integrated record, black on one side and white on the other. The band were just worried they might get run out of town. But if Sam had the ears of a veteran bluesman, he had the mind of a businessman. He knew the white kids loved what they heard of black music. And he knew that only a white man could capture their hearts — and persuade them to hand over their dollars.

Sam got the record played on the blues programme of the local white radio station. Elvis was dragged unwillingly into the station to be interviewed and to make it plain that he was, in fact, white. His popularity rocketed.

Then, in late 1955, shortly after the release of the incomparable "Mystery Train", Elvis was taken away from Sun and into the hands of a major label, RCA. There, his producer Steven Sholes started by imitating the Sun Sound before adding piano, louder drums, a sickly vocal group called The Jordanaires, and much more. Elvis now had the freedom to record what he liked. And what he liked, as much as he liked the blues, was the traditional repertoire of the crooner. The people at RCA liked his Dean Martin impression.

Sam put a brave new face on the loss. His first Elvis "replacement" Carl Perkins brought him a massive hit with "Blue Suede Shoes". But after Elvis, Sam forgot about the black men who had been his inspiration and concentrated instead on pressing any number of unsuitable singers into the rockabilly mould. Some rose above it, like Jerry Lee Lewis or Johnny Cash. Others, like Roy Orbison or Charlie Rich, went their own way.

By the time Elvis entered the army in March 1958 his days as a rock innovator were over. So too were Sun's, although the label managed to survive in some shape or form until 1968.

But between them they had been the originators and their impact went well beyond the narrow musical field. And today their influence is undimmed. Somewhere somebody is hearing the Sun sides for the first time — and rockabilly is casting its spell once again.

Essential listening:
"The Elvis Presley Sun Collection" (RCA NL 42757)
"Don't You Step On My Blue Suede Shoes" (Charly CR30119)
"Elvis The '56 Sessions Volume One" (RCA PL 42101)