The folklorist and song collector Harry Oster, who has died aged 77, was well known to blues enthusiasts for his vivid, unstereotypical recordings of African-American rural music. In fact he ranged more widely, across jazz, country and British folksong - interests he promoted both as teacher and as proprietor of a small record company.
Born in Cambridge, Massachusetts, the son of immigrant Russian Jews, he became interested in Yiddish folk song, but soon came to appreciate the whole patchwork of American vernacular music. While teaching at Louisiana State University, a well-received lecture on Old World traditional ballads prompted a colleague to suggest that he apply for a grant to collect local folklore.
"Before long," he recalled, "I found a profusion of unusual material - ancient French ballads, Cajun dance music, Afro-French spirituals... I got the idea that I should issue with my own funds a long-playing record to be called A Sampler of Louisiana Folk Songs." This and succeeding records such as Folk Songs of the Louisiana Acadians, the first LP of Cajun music, appeared under the auspices of the Louisiana Folklore Society, which Oster created with a couple of friends. Later recordings were on his own label, Folk-Lyric.
Oster's greatest discovery came on a trip to the state penitentiary at Angola. He was looking for African-American prison work songs, a genre documented earlier in recordings made for the Library of Congress, but now disappearing as prison farms became mechanised. The tradition in Angola was indeed moribund, but Oster found many impressive blues singers, among them Robert Pete Williams. The singer's intense improvised narratives about prison life and the events that had brought him there, were presented to the world on the 1959 album Angola Prisoner's Blues.
Oster also recorded the New Orleans singer and guitarist Snooks Eaglin, the fiddle-and-guitar duo Butch Cage and Willie Thomas, jazz musicians Billie and DeDe Pierce, old-timey banjoist Snuffy Jenkins and a street musician from Georgia, the Reverend Pearly Brown.
He left Louisiana in 1963 to teach at the University of Iowa, where he remained until his retirement in 1993, working on the American Dictionary of Folklore and pursuing his passion of making and disseminating records. His Folk-Lyric catalogue was acquired by Arhoolie Records and has largely been transferred to CD, and many of his field recordings were heard in 1995 in a BBC Radio 3 series devoted to his life and work.
He is survived by his wife and a son, Aaron.
• Harry Oster, folklorist, born April 17 1923; died January 19 2001.
