It wasn’t until 1958’s “Little Boy Blue,” a record inspired by the homiletic delivery of the Rev. C. L. Franklin, that Mr. Bland arrived at his trademark vocal technique.

“That’s where I got my squall from,” Mr. Bland said, referring to the sermons of Mr. Franklin — “Aretha’s daddy,” as he called him — in a 1979 interview with the author Peter Guralnick. “After I had that I lost the high falsetto. I had to get some other kind of gimmick, you know, to be identified with.”

The corresponding softness in Mr. Bland’s voice, a refinement matched by the elegant formal wear in which he appeared onstage, came from listening to records by pop crooners like Nat King Cole, Tony Bennett and Perry Como.

Just as crucial to the evolution of Mr. Bland’s sound was his affiliation with the trumpet player and arranger Joe Scott, for years the director of artists and repertory for Duke Records in Houston. Given to writing brass-rich arrangements that built dramatically to a climax, Mr. Scott, who died in 1979, supplied Mr. Bland with intricate musical backdrops that set his supple baritone in vivid emotional relief. The two men accounted for more than 30 Top 20 rhythm-and-blues singles for Duke from 1958 to 1968, including the No. 1 hits “I Pity the Fool” and “That’s the Way Love Is.” Steeped in feelings of vulnerability and regret, many of these performances were particularly enthralling to the female portion of Mr. Bland’s audience...