When the two Voyager probes were launched in 1977 on an interstellar journey projected to last for a billion years, each was fitted with a gold-plated copper disc containing ninety minutes of music from planet Earth. Should extraterrestrial beings ever have the desire and capability to listen to these discs, half of the tracks they hear will be selections made by one man. Thanks to Alan Lomax, works by Bach, Mozart and Stravinsky are complemented by recordings of folk music from the Solomon Islands, Peru, Java, Japan, Australia, India and Bulgaria, as well as by numbers performed by Louis Armstrong, Chuck Berry and Blind Willie Johnson. As Lomax’s biographer John Szwed observes, it remains ‘the ultimate mix tape’.

Merely reading Alan Lomax’s life is so exhausting that the notion of someone actually living it seems implausible. His primary occupation as an itinerant folklorist (‘Road Scholar’, in Szwed’s apt phrase) meant