Paul Oliver, probably the world’s foremost scholar of the blues, first heard African-American vernacular music during World War II when a friend brought him to listen to black servicemen stationed in England singing work songs they had brought with them from the fields and lumber camps of the Deep South.

Oliver was enthralled by the rhythm and drive of the music and the spontaneous interweaving of harmonies, and wanted to hear more. His fascination led him on a 60-year quest that has included numerous field trips through the American South interviewing, recording, and photographing blues musicians.

Born in 1927, Oliver is a fellow of the Royal Anthropological Institute, the University of Exeter, and Oxford Brookes University. In addition to being an expert on the blues and other African-American musical forms, he is also one of the world’s foremost authorities on vernacular architecture and is the editor of the four-volume “Encyclopedia of Vernacular Architecture of the World.” His books on the blues include “Blues Fell This Morning,” “Conversations with the Blues,” “Songsters and Saints: Vocal Traditions on Race Records,” and “The Story of the Blues.”

Oliver shared some of his insights into this rich, uniquely American music earlier this month, when he delivered the Alain LeRoy Locke Lectures, an annual series sponsored by the W.E.B. Du Bois Institute for African and African American Research.

In his talks, collectively titled “Proto Blues: Secular Black Music Recorded in the Field,” Oliver focused not only on the music that emerged in the early 20th century from the work camps, prison farms, juke joints, and vaudeville shows of the American South, but also on the circumstances under which that music was recorded.

Recording technology was barely past its infancy at the time, and the equipment required to make a decent recording of even a single performer accompanying himself on guitar weighed more than a ton and had to be transported by truck. As a result, making field recordings, which meant essentially bringing the recording studio to the performer, could be logistically challenging. Nevertheless, a significant number of collectors overcame those difficulties, motivated by aesthetic or commercial considerations, or both.

Oliver’s first lecture concentrated on commercial recordings made in the South between 1920 and 1930. In the 1920s, record companies discovered that there was a market for recordings of black musicians and began to comb the South for artists who had the potential to sell records. Setting up their equipment in hotel rooms in major cities, these emissaries from companies such as Victor, Paramount, Blue Bird, and Okeh recorded performances by artists who may have been local or brought from many miles away. A great deal of music was recorded in this fashion, but because the record companies concentrated on a handful of cities, much was undoubtedly lost to posterity.

“There were awfully big gaps between these locations, and whole genres of music may never have been recorded,” Oliver said.

Nevertheless, the range of artists Oliver played during his lecture was enough to strike listeners with the great variety of musical tributaries feeding into the blues. Among them was New Orleans musician Richard “Rabbit” Brown, known as the “Singing Boatman,” performing a ballad about the sinking of the Titanic; Clara Gibson, a vaudeville blues singer with a voice remarkably similar to that of the more famous Bessie Smith, but who made only one known recording; and Will Bennett, whose version of “Railroad Bill,” recounts the adventures of the famous badman hero, a legendary figure based on an actual 19th century bandit named Morris Slater.

What Oliver found interesting about Bennett’s version is the way the singer melds his own identity with that of his subject, prefiguring the autobiographical perspective of the majority of blues singers.

“In the first decades of the 20th century, there was a confluence of styles that led to the blues and ultimately to rock music,” he said.

Oliver’s second lecture focused on recordings from the Library of Congress Archive of Folk Music. Most of this music was collected by folklorist John Lomax and his son Alan, whose association with the Library of Congress gave them access to prison farms where they believed they would find examples of authentic folk music, untainted by the influence of popular entertainment.

The Lomaxes made many remarkable recordings. Among them, Oliver played a “ring shout,” recorded in 1934 in Louisiana, a type of group chant with roots in West Africa; a “tie-tamping song,” sung by railroad workers in Dallas; and an ax-cutting song, “Early in the Morning,” recorded on the Parchman Farm in Mississippi.

The Lomaxes recorded singers with more general appeal as well. One of their discoveries was Huddie Ledbetter, known as Leadbelly, who was serving time in a Louisiana prison. Impressed by his musical ability, vast repertoire, and charisma, the Lomaxes petitioned for his early release, and under their tutelage he relocated to New York City where he became a popular entertainer, recording artist, and friend of Woody Guthrie and Pete Seager.

Oliver played Ledbetter’s recording of “The Midnight Special,” which, he explained, was the train that brought wives and children to the prison for weekend visits.

Recordings made by collectors and aficionados was the theme of Oliver’s final lecture, a category that includes Oliver himself. Many of the bluesmen recorded by these independent collectors did not come to public attention until late in their careers, becoming icons of the folk revival of the 1950s and ’60s and playing to capacity crowds of mainly young, white enthusiasts.

This group includes Walter “Furry” Lewis, Mississippi John Hurt, and Manse Lipscomb, a Texas sharecropper who described himself as “a songster, not a blues singer,” whom Oliver recorded in the early 1960s.

The first recordings of Lipscomb were issued by Arhoolie Records, founded by Chris Strachwitz, one of the blues aficionados and collectors active during this period. The name Arhoolie was chosen because it is another word for “holler,” a type of musical call used to communicate with fellow workers in the cotton fields.

According to Oliver, these extemporaneous and expressive hollers converged with the more structured tunes of the songsters to produce the typical 12-bar blues form, consisting of an initial line repeated twice and followed by a concluding third line.

Many of the pieces Oliver played were recorded fairly recently, but with roots deep in the history of African-American folk culture. A 1970 recording of Othar Turner, a fife player who fashioned his own instruments from sections of hollow cane, performing with drummer Napolian Strickland, reflected a widespread musical tradition that may have begun around the time of the Civil War.

“Many of these traditions probably persisted longer than we realize,” Oliver said.