Otis Clay in 2012. (Brandon Dill/AP)

Otis Clay, a rhythm-and-blues singer and member of the Blues Hall of Fame who toured internationally and was known in his adopted city of Chicago for his charitable work, died Jan. 8 in Chicago. He was 73.

The cause was a heart attack, said a daughter, Ronda Tankson.

The Mississippi-born Mr. Clay displayed a gruff, tenor-tinged voice on blues songs such as “Trying to Live My Life Without You” and a haunting but hopeful baritone on gospel standards such as “When the Gates Swing Open.”

His manager, Miki Mulvehill, said Mr. Clay was planning a gospel tour of the United States followed by a European tour in the summer and, later, participation in the star-studded Legendary Rhythm and Blues Cruise. At the Blues Music Awards in May, he has been nominated for soul-blues male artist of the year, and “This Time for Real,” his collaboration with Billy Price, is up for soul-blues album.

“Otis was the last standard-bearer for deep Southern soul music, the really gospel-inflected music that was in its heyday in the late ’60s and early and mid-’70s,” Price said.

Otis Clay in 1966. (Courtesy of Otis Clay)

European music enthusiasts and record collectors flock to Mr. Clay’s music because of its spare, “unvarnished” style, wrought in the 1960s soul scenes in Memphis and Muscle Shoals, Ala., Price said.

Mr. Clay’s most recent solo album was “Truth Is,” released in 2013, the year he was inducted into the Blues Hall of Fame.

A resident of Chicago’s West Side, he was extensively involved in charitable work. Tankson, a Chicago special-education teacher whose pupils include autistic children, said her father gave little thought to what benefit he’d get from performing and held nothing back, even when appearing for her students. “He sang to them as if they paid and he was on stage,” she said.

Tankson said her friends and co-workers, whom Mr. Clay had never met, asked if he would sing “When the Gates Swing Open” at loved ones’ funerals. “He never let me down on that,” she said, adding that he once delayed a recording-session trip to Memphis to comply.

Mr. Clay was born in Waxhaw, Miss., on Feb. 11, 1942, to a musical and religious family. After his arrival in Chicago in 1957, he joined the Golden Jubilaires. In 1960, he became part of Charles Bridges’s Famous Blue Jay Singers, performing a cappella at schools and hotels.

“We were known as variety singers, or we were billed as [performing] ‘Old Negro Spirituals and Plantation Melodies,’ ” Mr. Clay said in his biography.

His recording debut came in 1965 with the rousing ballad “Flame in Your Heart.” Four decades later, in 2007, he was nominated for a Grammy for the gospel CD “Walk a Mile in My Shoes.”

A complete list of survivors was not immediately available.

Associated Press