Mr. King considered a 1968 performance at the Fillmore West, the San Francisco rock palace, to have been the moment of his commercial breakthrough, he told a public-television interviewer in 2003. A few years earlier, he recalled, an M.C. in an elegant Chicago club had introduced him thus: “O.K., folks, time to pull out your chitlin’s and your collard greens, your pigs’ feet and your watermelons, because here is B. B. King.” It had infuriated him.

When he saw “longhaired white people” lining up outside the Fillmore, he said, he told his road manager, “I think they booked us in the wrong place.” Then the promoter Bill Graham introduced him to the sold-out crowd: “Ladies and gentlemen, I bring you the chairman of the board, B. B. King.”

“Everybody stood up, and I cried,” Mr. King said. “That was the beginning of it.”

By his 80th birthday he was a millionaire many times over. He owned a mansion in Las Vegas, a closet full of embroidered tuxedos and smoking jackets, a chain of nightclubs bearing his name (including a popular room on West 42nd Street in Manhattan) and the personal and professional satisfaction of having endured.

Through it all he remained with the great love of his life, his guitar. He told the tale a thousand times: He was playing a dance hall in Twist, Ark., in the early 1950s when two men got into a fight and knocked over a kerosene stove. Mr. King fled the fire — and then remembered his $30 guitar. He ran into the burning building to rescue it.

He learned thereafter that the fight had been about a woman named Lucille. For the rest of his life, Mr. King addressed his guitars — big Gibsons, curved like a woman’s hips — as Lucille.