Paul Oliver. (Michael Roach/European Blues Association)

Paul Oliver, a British academic who wrote some of the first scholarly studies of blues music in the 1950s and 1960s, which helped spur a worldwide renewal of interest in the music, and who was also a prominent architectural historian, died Aug. 15 at a nursing center in Shipton-under-Wychwood, Oxfordshire, England. He was 90.

Michael Roach, founder of the European Blues Association, confirmed the death. Other details were not available.

Mr. Oliver was equally distinguished in both fields, although it was likely that aficionados of one of his specialties were not aware of his expertise in the other. He wrote or edited more than 10 books on each subject, including a biography of singer Bessie Smith and “The Story of the Blues,” often called the first comprehensive history of the music.

As an authority on “vernacular architecture,” or homegrown building styles designed by people who were not architects, he edited the monumental “Encyclopedia of Vernacular Architecture of the World,” a definitive tome that weighs 18 pounds.

In the United States, Mr. Oliver was better known for his work on the blues, which grew out of a teenage experience at a summer camp, where a friend named Stan played a record of field hollers.

Paul Oliver interviewing the blues artist Lightnin’ Hopkins in Houston in 1960. (Arhoolie Foundation/Chris Strachwitz)

“Suddenly the air seemed split by the most eerie sounds,” Mr. Oliver wrote years later. “The two men were singing, swooping, undulating, unintelligible words, and the back of my neck tingled. ‘They’re singing a blues,’ Stan hissed at me. It was the strangest, most compelling singing I’d ever heard.”

At first, Mr. Oliver combined his twin interests in art and music by painting covers for British blues albums in the 1950s. He also wrote essays for jazz magazines, exploring the various styles of blues and gospel music, before publishing his Smith biography in 1959. He made his first visit to the United States in 1960, roaming Northern cities and the still-segregated South to interview and photograph blues musicians, both famous and forgotten.

He spent hours with such musicians as Big Bill Broonzy, Sonny Terry and Brownie McGhee and helped rediscover other early masters who died young, including Charley Patton, Blind Lemon Jefferson and Peetie Wheatstraw . Mr. Oliver also journeyed throughout West Africa, exploring the origins of the blues.

“His main point of interest was always centered on the relationship between the music and the social environment in which it emerged,” British scholar Christian O’Connell wrote in his 2015 book about Mr. Oliver, “Blues, How Do You Do?”

Perhaps because he was not from the United States, Mr. Oliver brought a rare sensitivity to African American culture and treated the blues with a seriousness previously reserved for classical music and other fine arts.

“I am acutely aware of my remoteness from the environment that nurtured the blues,” he wrote in “Blues Fell This Morning” (1960).

In his books, including “Conversation With the Blues” (1965), “Screening the Blues” (1968) and “Savannah Syncopators” (1969), Mr. Oliver explored various blues traditions and how they grew from the regions and living circumstances of their creators.

“In an incredible accomplishment, he unravels a labyrinth of material about the African origins of black American music and adds his own sensitive scholarship,” music critic Hollie I. West wrote in The Washington Post in 1970. “While most writers have looked to Africa — primarily through second-hand sources — Oliver searched in person for the genesis of the blues.”

Paul Hereford Oliver was born May 25, 1927, in Nottingham, England. His father was an architect.

In addition to his interest in the blues, Mr. Oliver was skilled at drawing. After attending art school, he was an art teacher in English schools before graduating in 1955 from the University of London.

He became a lecturer in art history and architectural history and taught at several British colleges before ending up at the architecture school of Oxford Brookes University.

He wrote widely on vernacular architecture in Britain, Ghana, Turkey, Costa Rica and the United States in books such as “Dwellings: The House Across the World” (first published in 1987).

“It is remarkable that Oliver has had such a prominent career as a blues scholar,” O’Connell wrote in “Blues, How Do You Do?,” “considering that it has been secondary to his main profession as an architectural academic.”

Mr. Oliver’s wife of 52 years, the former Valerie Coxon, died in 2002. He did not have any immediate survivors.

Throughout his life, Mr. Oliver was a popular presence at blues festivals, where he sometimes served as an emcee or a member of scholarly panels.

He was named to the Blues Foundation’s Hall of Fame in Memphis in 2008.

In one of his final books about the blues, “Barrelhouse Blues” (2009), he continued to examine the evolution of the music and to rediscover lost musical treasures, such as Cleo Gibson’s racy 1929 recording “I’ve Got Ford Engine Movements in My Hips.”

After the publication of his 1997 magnum opus, the 2,500-page “Encyclopedia of Vernacular Architecture,” in which he coordinated the work of 780 contributors from more than 80 countries, Mr. Oliver summed up how the two diverse strands of his scholarly interests were ultimately interwoven.

“I’ve tried to redraw the cultural map of the world,” he said.