Allen Toussaint, one of the greatest exponents of New Orleans music, in all its many forms, died of a heart attack Nov. 10 while on tour in Spain. The Chicago Symphony Orchestra Association joins music lovers worldwide in mourning his sudden death at age 77.

The prolific pianist-composer-producer appeared in 2011 at Orchestra Hall while on tour for the album “The Bright Mississippi,” an homage to his native Crescent City, with trumpeter Nicholas Payton and clarinetist Don Byron. And just last week, during a Chicago Humanities Festival event at the Francis Parker Auditorium, rock icon Elvis Costello spoke glowingly of his collaboration with Mr. Toussaint on the 2006 album “The River in Reverse.”

Of the 2011 Symphony Center concert, the Chicago Tribune wrote: “Allen Toussaint celebrated his 73rd birthday Friday night by bringing his Grammy-nominated ‘The Bright Mississippi’ project to Orchestra Hall. In some ways, the evening transcended the recording. For starters, Toussaint pushed beyond the repertoire of “The Bright Mississippi,” singing his vintage hits with a radiant tenor and a Crescent City cadence. To hear him deliver songs such as “Get Out of My Life, Woman,” “What Do You Want the Girl to Do?” and “Southern Nights” was to revel in one of the more imploring voices in American music.”

In 2005, Sun-Times music columnist Dave Hoekstra interviewed Mr. Toussaint about the aftermath of Hurricane Katrina: “All my stuff downstairs is destroyed,” he said. “My Steinway piano. Equipment. My file cabinets — with loads of hand-written music — is gone as well. It’s a disaster zone. But I’ve resolved it’s the rearview mirror. I’m optimistic about the future. The city will be better.”

He also spoke about his songwriting process: “When I write, I don’t usually hear a plot without a melody. I might hear two people talking and that will inspire a story. But a little melody always comes with that. Always.”

RIP, Allen Toussaint. American roots music owes you an eternal debt.