BOOK REVIEW / Sun gonna shine some day: Godfrey Hodgson on the inspiring journeys of Alan Lomax, who revealed the magic of the blues for the world: The land where the Blues began - Alan Lomax: Methuen, pounds 20

IN 1933, when he was 17 years old, Alan Lomax went with his father to record songs sung by prisoners at the Central State prison farm in his native Texas. Their equipment was primitive: the recorder weighed 500lbs, and the aluminium discs lasted for only four minutes each. Still, the songs they recorded there - The Midnight Special, Little John Henry, and Me and My Buddy Pick a Bale of Cotton among them - had momentous consequences for young Alan Lomax, for black people in the Deep South and indeed for the world.

Lomax pere, John Lomax, was not a specialist in black music. He was a folk-song enthusiast who built up the Library of Congress's collection of recorded folk music under the benevolent protection of the librarian - the poet Archibald McLeish. Alan Lomax was spurred by those early recording trips in the prison farms of the Deep South to devote his life to recording, collecting and interpreting the blues. In 1942, just before going into the army, he made a recording trip to the area that was to be the scene of his life's work, the Mississippi Delta.

It was not easy. At one point he was arrested as a Japanese spy on the grounds that he had not only shaken hands with a black man, but had called him 'Mister', something, it was plain to the sheriff, that no good American could have done. But it was on this trip he made the first contacts that enabled him later to uncover whole dynasties of bluesmen. Lomax discovered and recorded many musicians of captivating talent, culminating in the 'melancholy and sensuous' songs of McKinley Morganfield of Clarksdale, Mississippi, better known to the world as Muddy Waters. Lomax rightly comments that the best compositions of this orphaned boy, who began work at the age of 10 for 50 cents a day, are 'as artful, as carefully structured as an 18th-century love lyric'.

In the first third of this century the Delta was a raw frontier, a crescent of rich black soil that was still being tamed behind the snaking green banks of the levee that holds back the Father of Waters for a thousand miles on both banks south of Memphis. This was the receding wilderness of Faulkner's greatest short story, The Bear. The back-breaking work of building the levee, clearing the timber, hosing and loading the cotton was done by black people who were the poorest and most oppressed in the whole of the United States. If they fell foul of the law, which was easy enough to do, they would be taken in chains to the prison farms, Parchman or Sugarland in Mississippi, Angola in Louisiana or similar hell-holes in Arkansas and Texas. There they worked in the fields, woods and quarries in the boiling sun under the jaundiced eye of white guards armed with whips and shotguns.

It was in these terrible places that Lomax recorded some of the most poignant singing. Some of them were rhythmic work songs, like the polyrhythmic songs of the woodchoppers, Twenty-two, Little Red, Tangle Eye and Hard Hair, as they swung their axes in pairs alternately and chanted in the woodlot at Parchman farm.

Some were solo 'hollers', cries of pain and despair from the lowest depths, fit to compare with the cante jondo of Andalusia. In one of them, a prison-singer calls on his long-dead mother to make his shroud: 'Mamam mamaaa, Come make me a garment, And make it long, white and narrow.'

Some were bawdy, some cheerful dance measures like the 'slow drag', once thought so indecent that white planters would bribe their own sharecroppers to let them watch it, but now approximated by the gyrations of young white middle-class boys and girls in every nightclub on earth. Out of these roots grew the blues as they were sung by Blind Lemon Jefferson, Son House, John Hurt, Big Bill Broonzy and Muddy Waters.

Lomax had found a life's work. He spent 20 years at Columbia University in New York attempting, with the help of computers and graduate students, to design 'cantometric' and 'choreometric' systems for analysing the world's styles of folk song and dancing. Occasionally some of his intriguing theories about the surival of African traditions in the music and dancing of the American South put their heads round the door and interrupt this autobiography. He advances fascinating pieces of lore, such as the fact that Mississippi black people inherited from their African ancestors a superstitious fear of 'foot-crossing', so that white people's dancing struck them as profoundly immoral.

Popular music was transformed everywhere by the discoveries Lomax made. Blues singers like Broonzy and Muddy Waters moved to Chicago, where they were scandalously exploited by the (white) businessmen who controlled the so-called 'race' record companies. Broonzy told Lomax he had earned no more than dollars 2,000 for 260 recorded compositions. But in the Sixties their music was picked up and imitated - unsuccessfully imitated, Lomax would argue, because their imitators did not understand the social or musical roots of African-American music - by white Americans and, especially, Europeans.

At the Beatles' first press conference in America, they were asked whom they most wanted to meet. They replied, 'Muddy Waters and Bo Diddley'. 'Where's that?' asked the reporter. Mick Jagger named the Rolling Stones after a line from a Muddy Waters song that Lomax recorded at the Sherrod plantation near Clarksdale in 1942. And Lomax is not being immodest when he claims that in the long run those early recording sessions led to 'a revolution in Tin Pan Alley'.

The key to Lomax's love of the music and the musicians is a saying of Leadbelly's, who served time for murder on a prison farm himself: 'It take a man that have the blues to sing the blues.'

To the telling of his obsessional journey in search of the blues, and to the evocation of the vanishing world of the Delta, Lomax brings a style of writing that echoes the music he loves: emotional, whimsical, sometimes sentimental, always passionate, flecked with insights he sometimes mentions so briefly they are almost thrown away. It must be the best book ever written about the most haunting and inspiring music ever to come out of America.

In his low-key way, Lomax makes an even bigger claim for his life's work. The blues he recorded, he says, helped 'to soften those time-hardened prejudices'. John Henry, the railroad track layer, 'put the Bill of Rights into one phrase: 'A man ain't nothing but a man.' ' Lomax turns to the blues - where else? - to end this elegiac and moving book on an up beat: 'The sun gonna shine in my back door some day. The wind gonna rise and blow my blues away.'