Radio 4 documentary reveals the politics behind fearless folkie Alan Lomax's work

Reviews: Archive on 4: Alan Lomax - Songs of Freedom, Radio 4; The Story of Sleater-Kinney, 6 Music

Alan Lomax was a musicologist and archivist whose impact on American culture was so vast, his death earned him a front-page obituary in The New York Times. His recordings, of which there are over 3,000 hours, became the authoritative collection of American blues and sparked the folk revival of the Sixties, introducing a new generation of singers to a treasure trove of traditional songs. All of which means we have him to blame for Bob Dylan.

But this week's Radio 4 documentary, Alan Lomax – Songs of Freedom, wasn't merely about the songs he unearthed, nor the scores of beardy strummers he begat.

This was about the politics behind his work, which, said his biographer, succeeded in "giving voice to the voiceless".

Narrated by Billy Bragg, the show argued that Lomax was more than a talent spotter and collector. He was also a fearless advocate of racial equality. With the advent of sound recording technology, Lomax realised that he was in a position to "give an avenue for the people who had no way to get their troubles told".

This was the latest in the Archive on 4 strand, which, for reasons I've yet to fathom, rarely puts a foot wrong. I've tried to find fault, because no series can be this perfect, but so far to no avail. Whether investigating William Burroughs' legacy or the media coverage of Patty Hearst, these hour-long, socio-political programmes are rigorously researched, beautifully produced and mesmerising in their detail.

And so it was in Songs of Freedom that there were excerpts from Lomax's lectures in which he spoke of his forays around the Deep South in the Thirties with his father (John Lomax was also an archivist who began his career collecting cowboy songs) and in which he noted: "America, for the first time, got to be confident about itself, about where its roads ran and where its tunes went."

We heard from Shirley Collins, the British folk singer who worked for a while as Lomax's assistant, and who recalled driving from Southern town to Southern town filled with KKK signs and with chain gangs at the side of the road.

We also heard from Lomax's daughter, Anna, who read out her father's essays that recounted gathering oral accounts of black hardship. "When I learned the full depth of their humiliation, it changed me for ever," he wrote.

Lomax recorded in 18 prisons, an experience that reinforced his disgust at the treatment of African-Americans. Once in a while, though, he was able to help. In a Louisiana jail he met Huddie Ledbetter, aka Lead Belly, who was serving a sentence for manslaughter. There, he recorded a song in which Lead Belly appealed to the governor of Louisiana to let him go free.

Lomax duly took the song to the governor who, through a veil of tears, issued a pardon. And lo, a folk legend was liberated.

"There's a desperation in our songs that people can relate to," said Carrie Brownstein in The Story of Sleater-Kinney on 6 Music.

While this documentary contained the inevitable slew of commentators explaining the legacy of an act that began life at the tail end of riot grrrl and was later hailed by Time magazine as "America's greatest rock band", the best thing about it was hearing two cool women – Brownstein and her bandmate Corin Tucker – tell their own story with all the wisdom that distance affords.

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