Walter Harding (1883-1973) was the son of an East End bricklayer who was taken to the US at the age of four and eventually made a living playing in silent cinemas and then a church.
Although he started off collecting music he could perform, he soon branched out to verse, drama, sheet valentines and opera.
Because much of this material was considered too ephemeral to be interesting or valuable, he had few rivals and was eventually able to build up the world's largest collection of popular songbooks and related miscellanies from the 17th and 18th centuries, including rare Italian part books, broadsheet ballads and miniature theatres.
Most of this was meticulously catalogued on handwritten cards.
The complete Harding collection weighed 22 tonnes and was packed into 900 boxes so that it could be transported to the Bodleian in two planes.
The operation was on such a scale that the library sought help from the Ministry of Defence.
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