Woody Guthrie was born on 14 July 1912 in Okemah, Oklahoma. He died in 1967 in relative obscurity, having been hospitalised for the last 15 years of his life. Yet his music continues to be an inspiration for musicians from Bob Dylan and Bruce Springsteen to Billy Bragg. The centenary of his birth has seen a flurry of new books, CDs and concerts celebrating his music.
His songs attack poverty, racism, fascism (he had a sticker on his guitar saying "This machine kills fascists") and the system that creates such evils. His songs are on the side of workers, which is why, in a world still ravaged with the same problems, his music retains such power.
Perhaps his most famous song is This Land is Your Land, written originally as a riposte to the patriotic song God Bless America. Ironically it is often taken to be patriotic and is frequently sung with three of its original verses missing - the verses attacking private property and hunger.
But This Land is Your Land still has the power to anger the right. When Pete Seeger and Bruce Springsteen sang it at Obama's inauguration concert in January 2009 the then Fox News commentator Glenn Beck fulminated that it "is a song about a progressive utopia with no ownership of property". Tom Morello sang the full version to a strike rally in Wisconsin last year, calling it "a revolutionary class-war anthem".
Guthrie moved to California in 1937, following hundreds of thousands of his fellow "dust bowl" refugees from Oklahoma. They were fleeing drought and destitution, hoping for a better life. Instead they were faced with police violence, brutal exploitation and appalling living conditions.
When Guthrie got his own radio show in Los Angeles he started writing songs about how the Okies (as the refugees were labelled) were treated. By 1938 Woody had made contact with the Communist Party (CP). He was impressed by the way they supported the Californian agricultural workers' struggles. He performed at strike benefits and CP events, delivering food relief to strikers and writing a regular column for the communist press.
In 1940 he moved to New York. He maintained his support for the CP during the Cold War and the McCarthy anti-communist witch-hunts because "the Communists have always been the hardest fighters for the trade unions and equal rights for every person of every colour".
That year his Dustbowl Ballads album was released, which included songs like Tom Joad, which retells the story of The Grapes of Wrath, John Steinbeck's classic novel about Californian migrants. In 1941 he joined the Almanac Singers and went on a nationwide tour singing to strike rallies and local unions. When the US joined the Second World War the Almanac Singers threw themselves into producing anti-fascist songs.
As well as singing about contemporary experiences, Woody sang about powerful episodes from working class history. For instance, the song Ludlow Massacre tells the story of a 1914 miners' strike in Ludlow, Colorado, which was brutally attacked by state troopers who killed 13 children. The song tells how the miners fought back, and ends with the line, "I said 'God Bless the Mineworkers Union'/And then I hung my head and cried".
For a time Guthrie was openly racist on his Californian radio show, until challenged by a black listener. His ideas changed dramatically from then on.
In 1946 a black Pacific War veteran, Isaac Woodard, tried to use a whites-only toilet in South Carolina. He was so savagely beaten he lost his sight. There was a New York benefit concert with Count Basie, Billie Holiday and others including Guthrie. Guthrie's song told Woodward's story: "I thought I fought on the islands to get rid of their kind/But I can see the fight lots plainer now that I am blind".
In January 1948 he read a newspaper report of a plane crash in California in which 28 Mexican deportees (who had been working in the same fields the Okies had ten years before) were killed alongside three white crew. The crew were all named but the Mexicans were just labelled deportees. He exploded with anger and wrote the song Deportee. Its chorus runs: "Goodbye to my Juan, goodbye Rosalita,/Adios mis amigos, Jesus y Maria/You won't have a name when you ride the big airplane/All they will call you is deportees".
Guthrie's attacks on capitalism, expressed brilliantly in his music, remain as fresh and relevant today as when he first wrote them.