Otis Clay: Singer hailed for his work in gospel and soul as well as his charitable work in his adopted city of Chicago

European enthusiasts and record-collectors flocked to Clay's music because of its spare, "unvarnished" style perfected in the 1960s soul scenes in Memphis, Tennessee and Muscle Shoals

Clay in 2012 during the Blues Music Awards in Memphis (AP)

Otis Clay was a rhythm and blues artist known as much for his big heart and charitable work in Chicago as for his singing. His voice could be gruff and tenor-tinged, on songs such as "Trying to Live My Life Without You" or a haunting but hopeful baritone on gospel standards like "When the Gates Swing Open".

"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," his manager Billy Price said. "These styles change, and different styles are in the forefront, but Otis was just as strong in the past five years ... For that reason, he was an icon for a lot of us who work in this genre."

He added that European enthusiasts and record-collectors flocked to Clay's music because of its spare, "unvarnished" style perfected in the 1960s soul scenes in Memphis, Tennessee and Muscle Shoals.

Inducted into the Blues Hall of Fame in 2013, Clay had just begun planning a gospel tour of the US, followed by a summer European tour and, later, the Legendary Rhythm and Blues Cruise. His last album was This Time For Real, which came out in 2015. But Clay, who moved to Chicago in 1957, was much more than a talented musician. Living on the city's West Side, he was actively involved in charitable work.

His daughter Ronda 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, adding that friends and co-workers of Tankson's, whom Clay had never met, repeatedly asked if he would sing "When the Gates Swing Open" at family funerals.

He was born in 1942 in Waxhaw, Mississippi, into a musical and religious family who moved to Muncie, Indiana. After he arrived in Chicago in 1957 he joined the Golden Jubilaires, then in 1960 became part of Charles Bridges' 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,"' he recalled. 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. He died of a heart attack.

Otis Clay, singer: born Waxhaw, Mississippi 11 February 1942; died Chicago 8 January 2016.