Born in Montgomery, Ala., Mr. Hubbard was 19 when he followed two older sisters to Boston. Because of racial tension in the South, “he felt he had a chance to have a better life here,’’ said his wife, Hind.

While honing his vocal and harmonica skills, he worked as a carpenter, plumber, and electrician. By the 1970s, he was playing bass and could work full time as a musician, often with his band, the Hot Ribs. Then came the blues jams at the 1369 club.

Mr. Hubbard “grew up singing gospel music and has the charisma to coax more than a few shy souls on stage,’’ longtime Globe music critic Steve Morse wrote in 1986, describing the scene and the host’s eye-catching outfit: white suit, bow tie, huge sunglasses.

At the Sunday afternoon gatherings, Morse wrote, “musicians and fans forget their cares and whoop it up before the next work week dawns.’’

A sharp dresser, Mr. Hubbard “always maintained a professional show,’’ said fellow musician Chris Stovall Brown. “Truth be told, it’s rather challenging to run a jam.’’

When deciding who should take the stage and when, Brown said, “you have to be a bit of a psychologist.’’

In the 1993 interview with the Globe, Mr. Hubbard described his approach to figuring out the best mix of musicians.

“I like to know people personally, instead of just getting them on a list,’’ he said. “I always get people who I know are professionals with the beginners, so they can monitor them and keep them in line.’’

One such beginner he helped turn into a pro was Debra Vinci, now a blues and soul singer for local band Hipsocket, who credited Mr. Hubbard with coaxing her to sing in public for the first time.

Years ago, she encountered him when he was between sets at a jam in the former Beach Club at Faneuil Hall. Striking up a conversation, they discussed Billie Holiday, and Vinci confided that she liked to sing herself.

“I was always shy,’’ she said, “never the type to belt it out.’’