The cause was cancer, his family said.

Mr. Callier's return in the 1990s was one of the great recalled-to-life stories in modern pop. At his peak, in songs from the '70s like "Dancing Girl" and "Occasional Rain," Mr. Callier sang spiritual rhapsodies that began with gentle guitar and built to orchestrated, uplifting climaxes. But commercial success eluded him, and by the time British fans began to seek him out, he had retired from music and was working as a computer programmer.

Before long, though, he was being invited to perform in London, and on his vacation time he flew there to play for clubs full of reverent fans. Beginning with "TimePeace" (Verve) in 1998, he released a stream of new albums — he finally left the day job in 1999 — and collaborated with Paul Weller, Beth Orton, the group Massive Attack and other artists.

"It was like a dream," Mr. Callier said of his comeback performances in an interview with The New York Times in 1998. "A couple of times I had to stop the show because it was just too over the top emotionally for me to continue. People knew all the words to my songs."

Terrence Orlando Callier (pronounced CAL-yur) was born in Chicago on May 24, 1945. Among his friends when he was growing up were Curtis Mayfield and Jerry Butler of the Impressions. While still in high school he recorded for Chess Records, the Chicago blues and R&B label, but his mother persuaded him to stay in school before starting a music career.

He attended the University of Illinois at Urbana-Champaign and became influenced by both the folk movement and John Coltrane. His debut album, "The New Folk Sound of Terry Callier," recorded in 1964 by the folklorist Samuel Charters, established that Mr. Callier was difficult to categorize. He sang traditional songs like "Cotton Eyed Joe" and "900 Miles" with a calm, low voice that evoked Josh White and Fred Neil, but the album's instrumentation — acoustic guitar and two basses, played sparingly — gave the recordings an atmosphere that was both intimate and otherworldly.

In 1970 he joined Mr. Butler's Chicago Songwriters Workshop, where he worked with Charles Stepney, a producer and arranger who also worked with Earth, Wind and Fire. Mr. Callier was a co-writer of the Dells' 1971 hit "The Love We Had (Stays on My Mind)" and in 1972 released his own album, "Occasional Rain," on the Cadet label, a Chess imprint. He released four more albums through 1978 on Cadet and Elektra, but by the end of the decade his career had slowed down.

Soon after recording a single, "I Don't Want to See Myself (Without You)," which he paid for himself, in 1982, he quit music and went to work as a programmer at the National Opinion Resource Center, an affiliate of the University of Chicago. Meanwhile his music was attracting a cult following among British soul-music collectors and D.J.'s, and around 1990 he got a call from Eddie Piller of the Acid Jazz label, who wanted to reissue "I Don't Want to See Myself."

Mr. Callier is survived by his daughter, Sundiata Callier-Dullum; his son, Dhoruba Somlyo; his companion, Shirley Austin; his brother, Michael Callier; and a grandson.

In 1998, Mr. Callier said he had no ill feelings about the course of his career.

"I feel very blessed for my success," he said. "Everything happens in its own time, and it happened when I could handle it. I didn't have to bend myself out of shape to make a living, I got a position in computer programming, and I put my daughter through college. It couldn't have been any better."